| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S E M _ R E S -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2014, Free Software Foundation, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 3, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING3. If not, go to -- |
| -- http://www.gnu.org/licenses for a complete copy of the license. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with Atree; use Atree; |
| with Checks; use Checks; |
| with Debug; use Debug; |
| with Debug_A; use Debug_A; |
| with Einfo; use Einfo; |
| with Errout; use Errout; |
| with Expander; use Expander; |
| with Exp_Disp; use Exp_Disp; |
| with Exp_Ch6; use Exp_Ch6; |
| with Exp_Ch7; use Exp_Ch7; |
| with Exp_Tss; use Exp_Tss; |
| with Exp_Util; use Exp_Util; |
| with Fname; use Fname; |
| with Freeze; use Freeze; |
| with Itypes; use Itypes; |
| with Lib; use Lib; |
| with Lib.Xref; use Lib.Xref; |
| with Namet; use Namet; |
| with Nmake; use Nmake; |
| with Nlists; use Nlists; |
| with Opt; use Opt; |
| with Output; use Output; |
| with Restrict; use Restrict; |
| with Rident; use Rident; |
| with Rtsfind; use Rtsfind; |
| with Sem; use Sem; |
| with Sem_Aux; use Sem_Aux; |
| with Sem_Aggr; use Sem_Aggr; |
| with Sem_Attr; use Sem_Attr; |
| with Sem_Cat; use Sem_Cat; |
| with Sem_Ch4; use Sem_Ch4; |
| with Sem_Ch6; use Sem_Ch6; |
| with Sem_Ch8; use Sem_Ch8; |
| with Sem_Ch13; use Sem_Ch13; |
| with Sem_Dim; use Sem_Dim; |
| with Sem_Disp; use Sem_Disp; |
| with Sem_Dist; use Sem_Dist; |
| with Sem_Elim; use Sem_Elim; |
| with Sem_Elab; use Sem_Elab; |
| with Sem_Eval; use Sem_Eval; |
| with Sem_Intr; use Sem_Intr; |
| with Sem_Util; use Sem_Util; |
| with Targparm; use Targparm; |
| with Sem_Type; use Sem_Type; |
| with Sem_Warn; use Sem_Warn; |
| with Sinfo; use Sinfo; |
| with Sinfo.CN; use Sinfo.CN; |
| with Snames; use Snames; |
| with Stand; use Stand; |
| with Stringt; use Stringt; |
| with Style; use Style; |
| with Tbuild; use Tbuild; |
| with Uintp; use Uintp; |
| with Urealp; use Urealp; |
| |
| package body Sem_Res is |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| -- Second pass (top-down) type checking and overload resolution procedures |
| -- Typ is the type required by context. These procedures propagate the type |
| -- information recursively to the descendants of N. If the node is not |
| -- overloaded, its Etype is established in the first pass. If overloaded, |
| -- the Resolve routines set the correct type. For arith. operators, the |
| -- Etype is the base type of the context. |
| |
| -- Note that Resolve_Attribute is separated off in Sem_Attr |
| |
| procedure Check_Discriminant_Use (N : Node_Id); |
| -- Enforce the restrictions on the use of discriminants when constraining |
| -- a component of a discriminated type (record or concurrent type). |
| |
| procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id); |
| -- Given a node for an operator associated with type T, check that |
| -- the operator is visible. Operators all of whose operands are |
| -- universal must be checked for visibility during resolution |
| -- because their type is not determinable based on their operands. |
| |
| procedure Check_Fully_Declared_Prefix |
| (Typ : Entity_Id; |
| Pref : Node_Id); |
| -- Check that the type of the prefix of a dereference is not incomplete |
| |
| function Check_Infinite_Recursion (N : Node_Id) return Boolean; |
| -- Given a call node, N, which is known to occur immediately within the |
| -- subprogram being called, determines whether it is a detectable case of |
| -- an infinite recursion, and if so, outputs appropriate messages. Returns |
| -- True if an infinite recursion is detected, and False otherwise. |
| |
| procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id); |
| -- If the type of the object being initialized uses the secondary stack |
| -- directly or indirectly, create a transient scope for the call to the |
| -- init proc. This is because we do not create transient scopes for the |
| -- initialization of individual components within the init proc itself. |
| -- Could be optimized away perhaps? |
| |
| procedure Check_No_Direct_Boolean_Operators (N : Node_Id); |
| -- N is the node for a logical operator. If the operator is predefined, and |
| -- the root type of the operands is Standard.Boolean, then a check is made |
| -- for restriction No_Direct_Boolean_Operators. This procedure also handles |
| -- the style check for Style_Check_Boolean_And_Or. |
| |
| function Is_Definite_Access_Type (E : Entity_Id) return Boolean; |
| -- Determine whether E is an access type declared by an access declaration, |
| -- and not an (anonymous) allocator type. |
| |
| function Is_Predefined_Op (Nam : Entity_Id) return Boolean; |
| -- Utility to check whether the entity for an operator is a predefined |
| -- operator, in which case the expression is left as an operator in the |
| -- tree (else it is rewritten into a call). An instance of an intrinsic |
| -- conversion operation may be given an operator name, but is not treated |
| -- like an operator. Note that an operator that is an imported back-end |
| -- builtin has convention Intrinsic, but is expected to be rewritten into |
| -- a call, so such an operator is not treated as predefined by this |
| -- predicate. |
| |
| procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id); |
| -- If a default expression in entry call N depends on the discriminants |
| -- of the task, it must be replaced with a reference to the discriminant |
| -- of the task being called. |
| |
| procedure Resolve_Op_Concat_Arg |
| (N : Node_Id; |
| Arg : Node_Id; |
| Typ : Entity_Id; |
| Is_Comp : Boolean); |
| -- Internal procedure for Resolve_Op_Concat to resolve one operand of |
| -- concatenation operator. The operand is either of the array type or of |
| -- the component type. If the operand is an aggregate, and the component |
| -- type is composite, this is ambiguous if component type has aggregates. |
| |
| procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id); |
| -- Does the first part of the work of Resolve_Op_Concat |
| |
| procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id); |
| -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand |
| -- has been resolved. See Resolve_Op_Concat for details. |
| |
| procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Call (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Null (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Range (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id); |
| |
| function Operator_Kind |
| (Op_Name : Name_Id; |
| Is_Binary : Boolean) return Node_Kind; |
| -- Utility to map the name of an operator into the corresponding Node. Used |
| -- by other node rewriting procedures. |
| |
| procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id); |
| -- Resolve actuals of call, and add default expressions for missing ones. |
| -- N is the Node_Id for the subprogram call, and Nam is the entity of the |
| -- called subprogram. |
| |
| procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id); |
| -- Called from Resolve_Call, when the prefix denotes an entry or element |
| -- of entry family. Actuals are resolved as for subprograms, and the node |
| -- is rebuilt as an entry call. Also called for protected operations. Typ |
| -- is the context type, which is used when the operation is a protected |
| -- function with no arguments, and the return value is indexed. |
| |
| procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id); |
| -- A call to a user-defined intrinsic operator is rewritten as a call to |
| -- the corresponding predefined operator, with suitable conversions. Note |
| -- that this applies only for intrinsic operators that denote predefined |
| -- operators, not ones that are intrinsic imports of back-end builtins. |
| |
| procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id); |
| -- Ditto, for unary operators (arithmetic ones and "not" on signed |
| -- integer types for VMS). |
| |
| procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id); |
| -- If an operator node resolves to a call to a user-defined operator, |
| -- rewrite the node as a function call. |
| |
| procedure Make_Call_Into_Operator |
| (N : Node_Id; |
| Typ : Entity_Id; |
| Op_Id : Entity_Id); |
| -- Inverse transformation: if an operator is given in functional notation, |
| -- then after resolving the node, transform into an operator node, so |
| -- that operands are resolved properly. Recall that predefined operators |
| -- do not have a full signature and special resolution rules apply. |
| |
| procedure Rewrite_Renamed_Operator |
| (N : Node_Id; |
| Op : Entity_Id; |
| Typ : Entity_Id); |
| -- An operator can rename another, e.g. in an instantiation. In that |
| -- case, the proper operator node must be constructed and resolved. |
| |
| procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id); |
| -- The String_Literal_Subtype is built for all strings that are not |
| -- operands of a static concatenation operation. If the argument is |
| -- not a N_String_Literal node, then the call has no effect. |
| |
| procedure Set_Slice_Subtype (N : Node_Id); |
| -- Build subtype of array type, with the range specified by the slice |
| |
| procedure Simplify_Type_Conversion (N : Node_Id); |
| -- Called after N has been resolved and evaluated, but before range checks |
| -- have been applied. Currently simplifies a combination of floating-point |
| -- to integer conversion and Truncation attribute. |
| |
| function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id; |
| -- A universal_fixed expression in an universal context is unambiguous if |
| -- there is only one applicable fixed point type. Determining whether there |
| -- is only one requires a search over all visible entities, and happens |
| -- only in very pathological cases (see 6115-006). |
| |
| ------------------------- |
| -- Ambiguous_Character -- |
| ------------------------- |
| |
| procedure Ambiguous_Character (C : Node_Id) is |
| E : Entity_Id; |
| |
| begin |
| if Nkind (C) = N_Character_Literal then |
| Error_Msg_N ("ambiguous character literal", C); |
| |
| -- First the ones in Standard |
| |
| Error_Msg_N ("\\possible interpretation: Character!", C); |
| Error_Msg_N ("\\possible interpretation: Wide_Character!", C); |
| |
| -- Include Wide_Wide_Character in Ada 2005 mode |
| |
| if Ada_Version >= Ada_2005 then |
| Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C); |
| end if; |
| |
| -- Now any other types that match |
| |
| E := Current_Entity (C); |
| while Present (E) loop |
| Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E)); |
| E := Homonym (E); |
| end loop; |
| end if; |
| end Ambiguous_Character; |
| |
| ------------------------- |
| -- Analyze_And_Resolve -- |
| ------------------------- |
| |
| procedure Analyze_And_Resolve (N : Node_Id) is |
| begin |
| Analyze (N); |
| Resolve (N); |
| end Analyze_And_Resolve; |
| |
| procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is |
| begin |
| Analyze (N); |
| Resolve (N, Typ); |
| end Analyze_And_Resolve; |
| |
| -- Versions with check(s) suppressed |
| |
| procedure Analyze_And_Resolve |
| (N : Node_Id; |
| Typ : Entity_Id; |
| Suppress : Check_Id) |
| is |
| Scop : constant Entity_Id := Current_Scope; |
| |
| begin |
| if Suppress = All_Checks then |
| declare |
| Sva : constant Suppress_Array := Scope_Suppress.Suppress; |
| begin |
| Scope_Suppress.Suppress := (others => True); |
| Analyze_And_Resolve (N, Typ); |
| Scope_Suppress.Suppress := Sva; |
| end; |
| |
| else |
| declare |
| Svg : constant Boolean := Scope_Suppress.Suppress (Suppress); |
| begin |
| Scope_Suppress.Suppress (Suppress) := True; |
| Analyze_And_Resolve (N, Typ); |
| Scope_Suppress.Suppress (Suppress) := Svg; |
| end; |
| end if; |
| |
| if Current_Scope /= Scop |
| and then Scope_Is_Transient |
| then |
| -- This can only happen if a transient scope was created for an inner |
| -- expression, which will be removed upon completion of the analysis |
| -- of an enclosing construct. The transient scope must have the |
| -- suppress status of the enclosing environment, not of this Analyze |
| -- call. |
| |
| Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress := |
| Scope_Suppress; |
| end if; |
| end Analyze_And_Resolve; |
| |
| procedure Analyze_And_Resolve |
| (N : Node_Id; |
| Suppress : Check_Id) |
| is |
| Scop : constant Entity_Id := Current_Scope; |
| |
| begin |
| if Suppress = All_Checks then |
| declare |
| Sva : constant Suppress_Array := Scope_Suppress.Suppress; |
| begin |
| Scope_Suppress.Suppress := (others => True); |
| Analyze_And_Resolve (N); |
| Scope_Suppress.Suppress := Sva; |
| end; |
| |
| else |
| declare |
| Svg : constant Boolean := Scope_Suppress.Suppress (Suppress); |
| begin |
| Scope_Suppress.Suppress (Suppress) := True; |
| Analyze_And_Resolve (N); |
| Scope_Suppress.Suppress (Suppress) := Svg; |
| end; |
| end if; |
| |
| if Current_Scope /= Scop and then Scope_Is_Transient then |
| Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress := |
| Scope_Suppress; |
| end if; |
| end Analyze_And_Resolve; |
| |
| ---------------------------- |
| -- Check_Discriminant_Use -- |
| ---------------------------- |
| |
| procedure Check_Discriminant_Use (N : Node_Id) is |
| PN : constant Node_Id := Parent (N); |
| Disc : constant Entity_Id := Entity (N); |
| P : Node_Id; |
| D : Node_Id; |
| |
| begin |
| -- Any use in a spec-expression is legal |
| |
| if In_Spec_Expression then |
| null; |
| |
| elsif Nkind (PN) = N_Range then |
| |
| -- Discriminant cannot be used to constrain a scalar type |
| |
| P := Parent (PN); |
| |
| if Nkind (P) = N_Range_Constraint |
| and then Nkind (Parent (P)) = N_Subtype_Indication |
| and then Nkind (Parent (Parent (P))) = N_Component_Definition |
| then |
| Error_Msg_N ("discriminant cannot constrain scalar type", N); |
| |
| elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then |
| |
| -- The following check catches the unusual case where a |
| -- discriminant appears within an index constraint that is part of |
| -- a larger expression within a constraint on a component, e.g. "C |
| -- : Int range 1 .. F (new A(1 .. D))". For now we only check case |
| -- of record components, and note that a similar check should also |
| -- apply in the case of discriminant constraints below. ??? |
| |
| -- Note that the check for N_Subtype_Declaration below is to |
| -- detect the valid use of discriminants in the constraints of a |
| -- subtype declaration when this subtype declaration appears |
| -- inside the scope of a record type (which is syntactically |
| -- illegal, but which may be created as part of derived type |
| -- processing for records). See Sem_Ch3.Build_Derived_Record_Type |
| -- for more info. |
| |
| if Ekind (Current_Scope) = E_Record_Type |
| and then Scope (Disc) = Current_Scope |
| and then not |
| (Nkind (Parent (P)) = N_Subtype_Indication |
| and then |
| Nkind_In (Parent (Parent (P)), N_Component_Definition, |
| N_Subtype_Declaration) |
| and then Paren_Count (N) = 0) |
| then |
| Error_Msg_N |
| ("discriminant must appear alone in component constraint", N); |
| return; |
| end if; |
| |
| -- Detect a common error: |
| |
| -- type R (D : Positive := 100) is record |
| -- Name : String (1 .. D); |
| -- end record; |
| |
| -- The default value causes an object of type R to be allocated |
| -- with room for Positive'Last characters. The RM does not mandate |
| -- the allocation of the maximum size, but that is what GNAT does |
| -- so we should warn the programmer that there is a problem. |
| |
| Check_Large : declare |
| SI : Node_Id; |
| T : Entity_Id; |
| TB : Node_Id; |
| CB : Entity_Id; |
| |
| function Large_Storage_Type (T : Entity_Id) return Boolean; |
| -- Return True if type T has a large enough range that any |
| -- array whose index type covered the whole range of the type |
| -- would likely raise Storage_Error. |
| |
| ------------------------ |
| -- Large_Storage_Type -- |
| ------------------------ |
| |
| function Large_Storage_Type (T : Entity_Id) return Boolean is |
| begin |
| -- The type is considered large if its bounds are known at |
| -- compile time and if it requires at least as many bits as |
| -- a Positive to store the possible values. |
| |
| return Compile_Time_Known_Value (Type_Low_Bound (T)) |
| and then Compile_Time_Known_Value (Type_High_Bound (T)) |
| and then |
| Minimum_Size (T, Biased => True) >= |
| RM_Size (Standard_Positive); |
| end Large_Storage_Type; |
| |
| -- Start of processing for Check_Large |
| |
| begin |
| -- Check that the Disc has a large range |
| |
| if not Large_Storage_Type (Etype (Disc)) then |
| goto No_Danger; |
| end if; |
| |
| -- If the enclosing type is limited, we allocate only the |
| -- default value, not the maximum, and there is no need for |
| -- a warning. |
| |
| if Is_Limited_Type (Scope (Disc)) then |
| goto No_Danger; |
| end if; |
| |
| -- Check that it is the high bound |
| |
| if N /= High_Bound (PN) |
| or else No (Discriminant_Default_Value (Disc)) |
| then |
| goto No_Danger; |
| end if; |
| |
| -- Check the array allows a large range at this bound. First |
| -- find the array |
| |
| SI := Parent (P); |
| |
| if Nkind (SI) /= N_Subtype_Indication then |
| goto No_Danger; |
| end if; |
| |
| T := Entity (Subtype_Mark (SI)); |
| |
| if not Is_Array_Type (T) then |
| goto No_Danger; |
| end if; |
| |
| -- Next, find the dimension |
| |
| TB := First_Index (T); |
| CB := First (Constraints (P)); |
| while True |
| and then Present (TB) |
| and then Present (CB) |
| and then CB /= PN |
| loop |
| Next_Index (TB); |
| Next (CB); |
| end loop; |
| |
| if CB /= PN then |
| goto No_Danger; |
| end if; |
| |
| -- Now, check the dimension has a large range |
| |
| if not Large_Storage_Type (Etype (TB)) then |
| goto No_Danger; |
| end if; |
| |
| -- Warn about the danger |
| |
| Error_Msg_N |
| ("??creation of & object may raise Storage_Error!", |
| Scope (Disc)); |
| |
| <<No_Danger>> |
| null; |
| |
| end Check_Large; |
| end if; |
| |
| -- Legal case is in index or discriminant constraint |
| |
| elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint, |
| N_Discriminant_Association) |
| then |
| if Paren_Count (N) > 0 then |
| Error_Msg_N |
| ("discriminant in constraint must appear alone", N); |
| |
| elsif Nkind (N) = N_Expanded_Name |
| and then Comes_From_Source (N) |
| then |
| Error_Msg_N |
| ("discriminant must appear alone as a direct name", N); |
| end if; |
| |
| return; |
| |
| -- Otherwise, context is an expression. It should not be within (i.e. a |
| -- subexpression of) a constraint for a component. |
| |
| else |
| D := PN; |
| P := Parent (PN); |
| while not Nkind_In (P, N_Component_Declaration, |
| N_Subtype_Indication, |
| N_Entry_Declaration) |
| loop |
| D := P; |
| P := Parent (P); |
| exit when No (P); |
| end loop; |
| |
| -- If the discriminant is used in an expression that is a bound of a |
| -- scalar type, an Itype is created and the bounds are attached to |
| -- its range, not to the original subtype indication. Such use is of |
| -- course a double fault. |
| |
| if (Nkind (P) = N_Subtype_Indication |
| and then Nkind_In (Parent (P), N_Component_Definition, |
| N_Derived_Type_Definition) |
| and then D = Constraint (P)) |
| |
| -- The constraint itself may be given by a subtype indication, |
| -- rather than by a more common discrete range. |
| |
| or else (Nkind (P) = N_Subtype_Indication |
| and then |
| Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint) |
| or else Nkind (P) = N_Entry_Declaration |
| or else Nkind (D) = N_Defining_Identifier |
| then |
| Error_Msg_N |
| ("discriminant in constraint must appear alone", N); |
| end if; |
| end if; |
| end Check_Discriminant_Use; |
| |
| -------------------------------- |
| -- Check_For_Visible_Operator -- |
| -------------------------------- |
| |
| procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is |
| begin |
| if Is_Invisible_Operator (N, T) then |
| Error_Msg_NE -- CODEFIX |
| ("operator for} is not directly visible!", N, First_Subtype (T)); |
| Error_Msg_N -- CODEFIX |
| ("use clause would make operation legal!", N); |
| end if; |
| end Check_For_Visible_Operator; |
| |
| ---------------------------------- |
| -- Check_Fully_Declared_Prefix -- |
| ---------------------------------- |
| |
| procedure Check_Fully_Declared_Prefix |
| (Typ : Entity_Id; |
| Pref : Node_Id) |
| is |
| begin |
| -- Check that the designated type of the prefix of a dereference is |
| -- not an incomplete type. This cannot be done unconditionally, because |
| -- dereferences of private types are legal in default expressions. This |
| -- case is taken care of in Check_Fully_Declared, called below. There |
| -- are also 2005 cases where it is legal for the prefix to be unfrozen. |
| |
| -- This consideration also applies to similar checks for allocators, |
| -- qualified expressions, and type conversions. |
| |
| -- An additional exception concerns other per-object expressions that |
| -- are not directly related to component declarations, in particular |
| -- representation pragmas for tasks. These will be per-object |
| -- expressions if they depend on discriminants or some global entity. |
| -- If the task has access discriminants, the designated type may be |
| -- incomplete at the point the expression is resolved. This resolution |
| -- takes place within the body of the initialization procedure, where |
| -- the discriminant is replaced by its discriminal. |
| |
| if Is_Entity_Name (Pref) |
| and then Ekind (Entity (Pref)) = E_In_Parameter |
| then |
| null; |
| |
| -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages |
| -- are handled by Analyze_Access_Attribute, Analyze_Assignment, |
| -- Analyze_Object_Renaming, and Freeze_Entity. |
| |
| elsif Ada_Version >= Ada_2005 |
| and then Is_Entity_Name (Pref) |
| and then Is_Access_Type (Etype (Pref)) |
| and then Ekind (Directly_Designated_Type (Etype (Pref))) = |
| E_Incomplete_Type |
| and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref))) |
| then |
| null; |
| else |
| Check_Fully_Declared (Typ, Parent (Pref)); |
| end if; |
| end Check_Fully_Declared_Prefix; |
| |
| ------------------------------ |
| -- Check_Infinite_Recursion -- |
| ------------------------------ |
| |
| function Check_Infinite_Recursion (N : Node_Id) return Boolean is |
| P : Node_Id; |
| C : Node_Id; |
| |
| function Same_Argument_List return Boolean; |
| -- Check whether list of actuals is identical to list of formals of |
| -- called function (which is also the enclosing scope). |
| |
| ------------------------ |
| -- Same_Argument_List -- |
| ------------------------ |
| |
| function Same_Argument_List return Boolean is |
| A : Node_Id; |
| F : Entity_Id; |
| Subp : Entity_Id; |
| |
| begin |
| if not Is_Entity_Name (Name (N)) then |
| return False; |
| else |
| Subp := Entity (Name (N)); |
| end if; |
| |
| F := First_Formal (Subp); |
| A := First_Actual (N); |
| while Present (F) and then Present (A) loop |
| if not Is_Entity_Name (A) |
| or else Entity (A) /= F |
| then |
| return False; |
| end if; |
| |
| Next_Actual (A); |
| Next_Formal (F); |
| end loop; |
| |
| return True; |
| end Same_Argument_List; |
| |
| -- Start of processing for Check_Infinite_Recursion |
| |
| begin |
| -- Special case, if this is a procedure call and is a call to the |
| -- current procedure with the same argument list, then this is for |
| -- sure an infinite recursion and we insert a call to raise SE. |
| |
| if Is_List_Member (N) |
| and then List_Length (List_Containing (N)) = 1 |
| and then Same_Argument_List |
| then |
| declare |
| P : constant Node_Id := Parent (N); |
| begin |
| if Nkind (P) = N_Handled_Sequence_Of_Statements |
| and then Nkind (Parent (P)) = N_Subprogram_Body |
| and then Is_Empty_List (Declarations (Parent (P))) |
| then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_N ("!infinite recursion<<", N); |
| Error_Msg_N ("\!Storage_Error [<<", N); |
| Insert_Action (N, |
| Make_Raise_Storage_Error (Sloc (N), |
| Reason => SE_Infinite_Recursion)); |
| return True; |
| end if; |
| end; |
| end if; |
| |
| -- If not that special case, search up tree, quitting if we reach a |
| -- construct (e.g. a conditional) that tells us that this is not a |
| -- case for an infinite recursion warning. |
| |
| C := N; |
| loop |
| P := Parent (C); |
| |
| -- If no parent, then we were not inside a subprogram, this can for |
| -- example happen when processing certain pragmas in a spec. Just |
| -- return False in this case. |
| |
| if No (P) then |
| return False; |
| end if; |
| |
| -- Done if we get to subprogram body, this is definitely an infinite |
| -- recursion case if we did not find anything to stop us. |
| |
| exit when Nkind (P) = N_Subprogram_Body; |
| |
| -- If appearing in conditional, result is false |
| |
| if Nkind_In (P, N_Or_Else, |
| N_And_Then, |
| N_Case_Expression, |
| N_Case_Statement, |
| N_If_Expression, |
| N_If_Statement) |
| then |
| return False; |
| |
| elsif Nkind (P) = N_Handled_Sequence_Of_Statements |
| and then C /= First (Statements (P)) |
| then |
| -- If the call is the expression of a return statement and the |
| -- actuals are identical to the formals, it's worth a warning. |
| -- However, we skip this if there is an immediately preceding |
| -- raise statement, since the call is never executed. |
| |
| -- Furthermore, this corresponds to a common idiom: |
| |
| -- function F (L : Thing) return Boolean is |
| -- begin |
| -- raise Program_Error; |
| -- return F (L); |
| -- end F; |
| |
| -- for generating a stub function |
| |
| if Nkind (Parent (N)) = N_Simple_Return_Statement |
| and then Same_Argument_List |
| then |
| exit when not Is_List_Member (Parent (N)); |
| |
| -- OK, return statement is in a statement list, look for raise |
| |
| declare |
| Nod : Node_Id; |
| |
| begin |
| -- Skip past N_Freeze_Entity nodes generated by expansion |
| |
| Nod := Prev (Parent (N)); |
| while Present (Nod) |
| and then Nkind (Nod) = N_Freeze_Entity |
| loop |
| Prev (Nod); |
| end loop; |
| |
| -- If no raise statement, give warning. We look at the |
| -- original node, because in the case of "raise ... with |
| -- ...", the node has been transformed into a call. |
| |
| exit when Nkind (Original_Node (Nod)) /= N_Raise_Statement |
| and then |
| (Nkind (Nod) not in N_Raise_xxx_Error |
| or else Present (Condition (Nod))); |
| end; |
| end if; |
| |
| return False; |
| |
| else |
| C := P; |
| end if; |
| end loop; |
| |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_N ("!possible infinite recursion<<", N); |
| Error_Msg_N ("\!??Storage_Error ]<<", N); |
| |
| return True; |
| end Check_Infinite_Recursion; |
| |
| ------------------------------- |
| -- Check_Initialization_Call -- |
| ------------------------------- |
| |
| procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is |
| Typ : constant Entity_Id := Etype (First_Formal (Nam)); |
| |
| function Uses_SS (T : Entity_Id) return Boolean; |
| -- Check whether the creation of an object of the type will involve |
| -- use of the secondary stack. If T is a record type, this is true |
| -- if the expression for some component uses the secondary stack, e.g. |
| -- through a call to a function that returns an unconstrained value. |
| -- False if T is controlled, because cleanups occur elsewhere. |
| |
| ------------- |
| -- Uses_SS -- |
| ------------- |
| |
| function Uses_SS (T : Entity_Id) return Boolean is |
| Comp : Entity_Id; |
| Expr : Node_Id; |
| Full_Type : Entity_Id := Underlying_Type (T); |
| |
| begin |
| -- Normally we want to use the underlying type, but if it's not set |
| -- then continue with T. |
| |
| if not Present (Full_Type) then |
| Full_Type := T; |
| end if; |
| |
| if Is_Controlled (Full_Type) then |
| return False; |
| |
| elsif Is_Array_Type (Full_Type) then |
| return Uses_SS (Component_Type (Full_Type)); |
| |
| elsif Is_Record_Type (Full_Type) then |
| Comp := First_Component (Full_Type); |
| while Present (Comp) loop |
| if Ekind (Comp) = E_Component |
| and then Nkind (Parent (Comp)) = N_Component_Declaration |
| then |
| -- The expression for a dynamic component may be rewritten |
| -- as a dereference, so retrieve original node. |
| |
| Expr := Original_Node (Expression (Parent (Comp))); |
| |
| -- Return True if the expression is a call to a function |
| -- (including an attribute function such as Image, or a |
| -- user-defined operator) with a result that requires a |
| -- transient scope. |
| |
| if (Nkind (Expr) = N_Function_Call |
| or else Nkind (Expr) in N_Op |
| or else (Nkind (Expr) = N_Attribute_Reference |
| and then Present (Expressions (Expr)))) |
| and then Requires_Transient_Scope (Etype (Expr)) |
| then |
| return True; |
| |
| elsif Uses_SS (Etype (Comp)) then |
| return True; |
| end if; |
| end if; |
| |
| Next_Component (Comp); |
| end loop; |
| |
| return False; |
| |
| else |
| return False; |
| end if; |
| end Uses_SS; |
| |
| -- Start of processing for Check_Initialization_Call |
| |
| begin |
| -- Establish a transient scope if the type needs it |
| |
| if Uses_SS (Typ) then |
| Establish_Transient_Scope (First_Actual (N), Sec_Stack => True); |
| end if; |
| end Check_Initialization_Call; |
| |
| --------------------------------------- |
| -- Check_No_Direct_Boolean_Operators -- |
| --------------------------------------- |
| |
| procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is |
| begin |
| if Scope (Entity (N)) = Standard_Standard |
| and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean |
| then |
| -- Restriction only applies to original source code |
| |
| if Comes_From_Source (N) then |
| Check_Restriction (No_Direct_Boolean_Operators, N); |
| end if; |
| end if; |
| |
| -- Do style check (but skip if in instance, error is on template) |
| |
| if Style_Check then |
| if not In_Instance then |
| Check_Boolean_Operator (N); |
| end if; |
| end if; |
| end Check_No_Direct_Boolean_Operators; |
| |
| ------------------------------ |
| -- Check_Parameterless_Call -- |
| ------------------------------ |
| |
| procedure Check_Parameterless_Call (N : Node_Id) is |
| Nam : Node_Id; |
| |
| function Prefix_Is_Access_Subp return Boolean; |
| -- If the prefix is of an access_to_subprogram type, the node must be |
| -- rewritten as a call. Ditto if the prefix is overloaded and all its |
| -- interpretations are access to subprograms. |
| |
| --------------------------- |
| -- Prefix_Is_Access_Subp -- |
| --------------------------- |
| |
| function Prefix_Is_Access_Subp return Boolean is |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| -- If the context is an attribute reference that can apply to |
| -- functions, this is never a parameterless call (RM 4.1.4(6)). |
| |
| if Nkind (Parent (N)) = N_Attribute_Reference |
| and then Nam_In (Attribute_Name (Parent (N)), Name_Address, |
| Name_Code_Address, |
| Name_Access) |
| then |
| return False; |
| end if; |
| |
| if not Is_Overloaded (N) then |
| return |
| Ekind (Etype (N)) = E_Subprogram_Type |
| and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type; |
| else |
| Get_First_Interp (N, I, It); |
| while Present (It.Typ) loop |
| if Ekind (It.Typ) /= E_Subprogram_Type |
| or else Base_Type (Etype (It.Typ)) = Standard_Void_Type |
| then |
| return False; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| return True; |
| end if; |
| end Prefix_Is_Access_Subp; |
| |
| -- Start of processing for Check_Parameterless_Call |
| |
| begin |
| -- Defend against junk stuff if errors already detected |
| |
| if Total_Errors_Detected /= 0 then |
| if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then |
| return; |
| elsif Nkind (N) in N_Has_Chars |
| and then Chars (N) in Error_Name_Or_No_Name |
| then |
| return; |
| end if; |
| |
| Require_Entity (N); |
| end if; |
| |
| -- If the context expects a value, and the name is a procedure, this is |
| -- most likely a missing 'Access. Don't try to resolve the parameterless |
| -- call, error will be caught when the outer call is analyzed. |
| |
| if Is_Entity_Name (N) |
| and then Ekind (Entity (N)) = E_Procedure |
| and then not Is_Overloaded (N) |
| and then |
| Nkind_In (Parent (N), N_Parameter_Association, |
| N_Function_Call, |
| N_Procedure_Call_Statement) |
| then |
| return; |
| end if; |
| |
| -- Rewrite as call if overloadable entity that is (or could be, in the |
| -- overloaded case) a function call. If we know for sure that the entity |
| -- is an enumeration literal, we do not rewrite it. |
| |
| -- If the entity is the name of an operator, it cannot be a call because |
| -- operators cannot have default parameters. In this case, this must be |
| -- a string whose contents coincide with an operator name. Set the kind |
| -- of the node appropriately. |
| |
| if (Is_Entity_Name (N) |
| and then Nkind (N) /= N_Operator_Symbol |
| and then Is_Overloadable (Entity (N)) |
| and then (Ekind (Entity (N)) /= E_Enumeration_Literal |
| or else Is_Overloaded (N))) |
| |
| -- Rewrite as call if it is an explicit dereference of an expression of |
| -- a subprogram access type, and the subprogram type is not that of a |
| -- procedure or entry. |
| |
| or else |
| (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp) |
| |
| -- Rewrite as call if it is a selected component which is a function, |
| -- this is the case of a call to a protected function (which may be |
| -- overloaded with other protected operations). |
| |
| or else |
| (Nkind (N) = N_Selected_Component |
| and then (Ekind (Entity (Selector_Name (N))) = E_Function |
| or else |
| (Ekind_In (Entity (Selector_Name (N)), E_Entry, |
| E_Procedure) |
| and then Is_Overloaded (Selector_Name (N))))) |
| |
| -- If one of the above three conditions is met, rewrite as call. Apply |
| -- the rewriting only once. |
| |
| then |
| if Nkind (Parent (N)) /= N_Function_Call |
| or else N /= Name (Parent (N)) |
| then |
| |
| -- This may be a prefixed call that was not fully analyzed, e.g. |
| -- an actual in an instance. |
| |
| if Ada_Version >= Ada_2005 |
| and then Nkind (N) = N_Selected_Component |
| and then Is_Dispatching_Operation (Entity (Selector_Name (N))) |
| then |
| Analyze_Selected_Component (N); |
| |
| if Nkind (N) /= N_Selected_Component then |
| return; |
| end if; |
| end if; |
| |
| Nam := New_Copy (N); |
| |
| -- If overloaded, overload set belongs to new copy |
| |
| Save_Interps (N, Nam); |
| |
| -- Change node to parameterless function call (note that the |
| -- Parameter_Associations associations field is left set to Empty, |
| -- its normal default value since there are no parameters) |
| |
| Change_Node (N, N_Function_Call); |
| Set_Name (N, Nam); |
| Set_Sloc (N, Sloc (Nam)); |
| Analyze_Call (N); |
| end if; |
| |
| elsif Nkind (N) = N_Parameter_Association then |
| Check_Parameterless_Call (Explicit_Actual_Parameter (N)); |
| |
| elsif Nkind (N) = N_Operator_Symbol then |
| Change_Operator_Symbol_To_String_Literal (N); |
| Set_Is_Overloaded (N, False); |
| Set_Etype (N, Any_String); |
| end if; |
| end Check_Parameterless_Call; |
| |
| ----------------------------- |
| -- Is_Definite_Access_Type -- |
| ----------------------------- |
| |
| function Is_Definite_Access_Type (E : Entity_Id) return Boolean is |
| Btyp : constant Entity_Id := Base_Type (E); |
| begin |
| return Ekind (Btyp) = E_Access_Type |
| or else (Ekind (Btyp) = E_Access_Subprogram_Type |
| and then Comes_From_Source (Btyp)); |
| end Is_Definite_Access_Type; |
| |
| ---------------------- |
| -- Is_Predefined_Op -- |
| ---------------------- |
| |
| function Is_Predefined_Op (Nam : Entity_Id) return Boolean is |
| begin |
| -- Predefined operators are intrinsic subprograms |
| |
| if not Is_Intrinsic_Subprogram (Nam) then |
| return False; |
| end if; |
| |
| -- A call to a back-end builtin is never a predefined operator |
| |
| if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then |
| return False; |
| end if; |
| |
| return not Is_Generic_Instance (Nam) |
| and then Chars (Nam) in Any_Operator_Name |
| and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam))); |
| end Is_Predefined_Op; |
| |
| ----------------------------- |
| -- Make_Call_Into_Operator -- |
| ----------------------------- |
| |
| procedure Make_Call_Into_Operator |
| (N : Node_Id; |
| Typ : Entity_Id; |
| Op_Id : Entity_Id) |
| is |
| Op_Name : constant Name_Id := Chars (Op_Id); |
| Act1 : Node_Id := First_Actual (N); |
| Act2 : Node_Id := Next_Actual (Act1); |
| Error : Boolean := False; |
| Func : constant Entity_Id := Entity (Name (N)); |
| Is_Binary : constant Boolean := Present (Act2); |
| Op_Node : Node_Id; |
| Opnd_Type : Entity_Id; |
| Orig_Type : Entity_Id := Empty; |
| Pack : Entity_Id; |
| |
| type Kind_Test is access function (E : Entity_Id) return Boolean; |
| |
| function Operand_Type_In_Scope (S : Entity_Id) return Boolean; |
| -- If the operand is not universal, and the operator is given by an |
| -- expanded name, verify that the operand has an interpretation with a |
| -- type defined in the given scope of the operator. |
| |
| function Type_In_P (Test : Kind_Test) return Entity_Id; |
| -- Find a type of the given class in package Pack that contains the |
| -- operator. |
| |
| --------------------------- |
| -- Operand_Type_In_Scope -- |
| --------------------------- |
| |
| function Operand_Type_In_Scope (S : Entity_Id) return Boolean is |
| Nod : constant Node_Id := Right_Opnd (Op_Node); |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| if not Is_Overloaded (Nod) then |
| return Scope (Base_Type (Etype (Nod))) = S; |
| |
| else |
| Get_First_Interp (Nod, I, It); |
| while Present (It.Typ) loop |
| if Scope (Base_Type (It.Typ)) = S then |
| return True; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| return False; |
| end if; |
| end Operand_Type_In_Scope; |
| |
| --------------- |
| -- Type_In_P -- |
| --------------- |
| |
| function Type_In_P (Test : Kind_Test) return Entity_Id is |
| E : Entity_Id; |
| |
| function In_Decl return Boolean; |
| -- Verify that node is not part of the type declaration for the |
| -- candidate type, which would otherwise be invisible. |
| |
| ------------- |
| -- In_Decl -- |
| ------------- |
| |
| function In_Decl return Boolean is |
| Decl_Node : constant Node_Id := Parent (E); |
| N2 : Node_Id; |
| |
| begin |
| N2 := N; |
| |
| if Etype (E) = Any_Type then |
| return True; |
| |
| elsif No (Decl_Node) then |
| return False; |
| |
| else |
| while Present (N2) |
| and then Nkind (N2) /= N_Compilation_Unit |
| loop |
| if N2 = Decl_Node then |
| return True; |
| else |
| N2 := Parent (N2); |
| end if; |
| end loop; |
| |
| return False; |
| end if; |
| end In_Decl; |
| |
| -- Start of processing for Type_In_P |
| |
| begin |
| -- If the context type is declared in the prefix package, this is the |
| -- desired base type. |
| |
| if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then |
| return Base_Type (Typ); |
| |
| else |
| E := First_Entity (Pack); |
| while Present (E) loop |
| if Test (E) |
| and then not In_Decl |
| then |
| return E; |
| end if; |
| |
| Next_Entity (E); |
| end loop; |
| |
| return Empty; |
| end if; |
| end Type_In_P; |
| |
| -- Start of processing for Make_Call_Into_Operator |
| |
| begin |
| Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N)); |
| |
| -- Binary operator |
| |
| if Is_Binary then |
| Set_Left_Opnd (Op_Node, Relocate_Node (Act1)); |
| Set_Right_Opnd (Op_Node, Relocate_Node (Act2)); |
| Save_Interps (Act1, Left_Opnd (Op_Node)); |
| Save_Interps (Act2, Right_Opnd (Op_Node)); |
| Act1 := Left_Opnd (Op_Node); |
| Act2 := Right_Opnd (Op_Node); |
| |
| -- Unary operator |
| |
| else |
| Set_Right_Opnd (Op_Node, Relocate_Node (Act1)); |
| Save_Interps (Act1, Right_Opnd (Op_Node)); |
| Act1 := Right_Opnd (Op_Node); |
| end if; |
| |
| -- If the operator is denoted by an expanded name, and the prefix is |
| -- not Standard, but the operator is a predefined one whose scope is |
| -- Standard, then this is an implicit_operator, inserted as an |
| -- interpretation by the procedure of the same name. This procedure |
| -- overestimates the presence of implicit operators, because it does |
| -- not examine the type of the operands. Verify now that the operand |
| -- type appears in the given scope. If right operand is universal, |
| -- check the other operand. In the case of concatenation, either |
| -- argument can be the component type, so check the type of the result. |
| -- If both arguments are literals, look for a type of the right kind |
| -- defined in the given scope. This elaborate nonsense is brought to |
| -- you courtesy of b33302a. The type itself must be frozen, so we must |
| -- find the type of the proper class in the given scope. |
| |
| -- A final wrinkle is the multiplication operator for fixed point types, |
| -- which is defined in Standard only, and not in the scope of the |
| -- fixed point type itself. |
| |
| if Nkind (Name (N)) = N_Expanded_Name then |
| Pack := Entity (Prefix (Name (N))); |
| |
| -- If this is a package renaming, get renamed entity, which will be |
| -- the scope of the operands if operaton is type-correct. |
| |
| if Present (Renamed_Entity (Pack)) then |
| Pack := Renamed_Entity (Pack); |
| end if; |
| |
| -- If the entity being called is defined in the given package, it is |
| -- a renaming of a predefined operator, and known to be legal. |
| |
| if Scope (Entity (Name (N))) = Pack |
| and then Pack /= Standard_Standard |
| then |
| null; |
| |
| -- Visibility does not need to be checked in an instance: if the |
| -- operator was not visible in the generic it has been diagnosed |
| -- already, else there is an implicit copy of it in the instance. |
| |
| elsif In_Instance then |
| null; |
| |
| elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide) |
| and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node))) |
| and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node))) |
| then |
| if Pack /= Standard_Standard then |
| Error := True; |
| end if; |
| |
| -- Ada 2005 AI-420: Predefined equality on Universal_Access is |
| -- available. |
| |
| elsif Ada_Version >= Ada_2005 |
| and then Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne) |
| and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type |
| then |
| null; |
| |
| else |
| Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node))); |
| |
| if Op_Name = Name_Op_Concat then |
| Opnd_Type := Base_Type (Typ); |
| |
| elsif (Scope (Opnd_Type) = Standard_Standard |
| and then Is_Binary) |
| or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference |
| and then Is_Binary |
| and then not Comes_From_Source (Opnd_Type)) |
| then |
| Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node))); |
| end if; |
| |
| if Scope (Opnd_Type) = Standard_Standard then |
| |
| -- Verify that the scope contains a type that corresponds to |
| -- the given literal. Optimize the case where Pack is Standard. |
| |
| if Pack /= Standard_Standard then |
| |
| if Opnd_Type = Universal_Integer then |
| Orig_Type := Type_In_P (Is_Integer_Type'Access); |
| |
| elsif Opnd_Type = Universal_Real then |
| Orig_Type := Type_In_P (Is_Real_Type'Access); |
| |
| elsif Opnd_Type = Any_String then |
| Orig_Type := Type_In_P (Is_String_Type'Access); |
| |
| elsif Opnd_Type = Any_Access then |
| Orig_Type := Type_In_P (Is_Definite_Access_Type'Access); |
| |
| elsif Opnd_Type = Any_Composite then |
| Orig_Type := Type_In_P (Is_Composite_Type'Access); |
| |
| if Present (Orig_Type) then |
| if Has_Private_Component (Orig_Type) then |
| Orig_Type := Empty; |
| else |
| Set_Etype (Act1, Orig_Type); |
| |
| if Is_Binary then |
| Set_Etype (Act2, Orig_Type); |
| end if; |
| end if; |
| end if; |
| |
| else |
| Orig_Type := Empty; |
| end if; |
| |
| Error := No (Orig_Type); |
| end if; |
| |
| elsif Ekind (Opnd_Type) = E_Allocator_Type |
| and then No (Type_In_P (Is_Definite_Access_Type'Access)) |
| then |
| Error := True; |
| |
| -- If the type is defined elsewhere, and the operator is not |
| -- defined in the given scope (by a renaming declaration, e.g.) |
| -- then this is an error as well. If an extension of System is |
| -- present, and the type may be defined there, Pack must be |
| -- System itself. |
| |
| elsif Scope (Opnd_Type) /= Pack |
| and then Scope (Op_Id) /= Pack |
| and then (No (System_Aux_Id) |
| or else Scope (Opnd_Type) /= System_Aux_Id |
| or else Pack /= Scope (System_Aux_Id)) |
| then |
| if not Is_Overloaded (Right_Opnd (Op_Node)) then |
| Error := True; |
| else |
| Error := not Operand_Type_In_Scope (Pack); |
| end if; |
| |
| elsif Pack = Standard_Standard |
| and then not Operand_Type_In_Scope (Standard_Standard) |
| then |
| Error := True; |
| end if; |
| end if; |
| |
| if Error then |
| Error_Msg_Node_2 := Pack; |
| Error_Msg_NE |
| ("& not declared in&", N, Selector_Name (Name (N))); |
| Set_Etype (N, Any_Type); |
| return; |
| |
| -- Detect a mismatch between the context type and the result type |
| -- in the named package, which is otherwise not detected if the |
| -- operands are universal. Check is only needed if source entity is |
| -- an operator, not a function that renames an operator. |
| |
| elsif Nkind (Parent (N)) /= N_Type_Conversion |
| and then Ekind (Entity (Name (N))) = E_Operator |
| and then Is_Numeric_Type (Typ) |
| and then not Is_Universal_Numeric_Type (Typ) |
| and then Scope (Base_Type (Typ)) /= Pack |
| and then not In_Instance |
| then |
| if Is_Fixed_Point_Type (Typ) |
| and then Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide) |
| then |
| -- Already checked above |
| |
| null; |
| |
| -- Operator may be defined in an extension of System |
| |
| elsif Present (System_Aux_Id) |
| and then Scope (Opnd_Type) = System_Aux_Id |
| then |
| null; |
| |
| else |
| -- Could we use Wrong_Type here??? (this would require setting |
| -- Etype (N) to the actual type found where Typ was expected). |
| |
| Error_Msg_NE ("expect }", N, Typ); |
| end if; |
| end if; |
| end if; |
| |
| Set_Chars (Op_Node, Op_Name); |
| |
| if not Is_Private_Type (Etype (N)) then |
| Set_Etype (Op_Node, Base_Type (Etype (N))); |
| else |
| Set_Etype (Op_Node, Etype (N)); |
| end if; |
| |
| -- If this is a call to a function that renames a predefined equality, |
| -- the renaming declaration provides a type that must be used to |
| -- resolve the operands. This must be done now because resolution of |
| -- the equality node will not resolve any remaining ambiguity, and it |
| -- assumes that the first operand is not overloaded. |
| |
| if Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne) |
| and then Ekind (Func) = E_Function |
| and then Is_Overloaded (Act1) |
| then |
| Resolve (Act1, Base_Type (Etype (First_Formal (Func)))); |
| Resolve (Act2, Base_Type (Etype (First_Formal (Func)))); |
| end if; |
| |
| Set_Entity (Op_Node, Op_Id); |
| Generate_Reference (Op_Id, N, ' '); |
| |
| -- Do rewrite setting Comes_From_Source on the result if the original |
| -- call came from source. Although it is not strictly the case that the |
| -- operator as such comes from the source, logically it corresponds |
| -- exactly to the function call in the source, so it should be marked |
| -- this way (e.g. to make sure that validity checks work fine). |
| |
| declare |
| CS : constant Boolean := Comes_From_Source (N); |
| begin |
| Rewrite (N, Op_Node); |
| Set_Comes_From_Source (N, CS); |
| end; |
| |
| -- If this is an arithmetic operator and the result type is private, |
| -- the operands and the result must be wrapped in conversion to |
| -- expose the underlying numeric type and expand the proper checks, |
| -- e.g. on division. |
| |
| if Is_Private_Type (Typ) then |
| case Nkind (N) is |
| when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide | |
| N_Op_Expon | N_Op_Mod | N_Op_Rem => |
| Resolve_Intrinsic_Operator (N, Typ); |
| |
| when N_Op_Plus | N_Op_Minus | N_Op_Abs => |
| Resolve_Intrinsic_Unary_Operator (N, Typ); |
| |
| when others => |
| Resolve (N, Typ); |
| end case; |
| else |
| Resolve (N, Typ); |
| end if; |
| |
| -- If in ASIS_Mode, propagate operand types to original actuals of |
| -- function call, which would otherwise not be fully resolved. If |
| -- the call has already been constant-folded, nothing to do. We |
| -- relocate the operand nodes rather than copy them, to preserve |
| -- original_node pointers, given that the operands themselves may |
| -- have been rewritten. |
| |
| if ASIS_Mode and then Nkind (N) in N_Op then |
| if Is_Binary then |
| Rewrite (First (Parameter_Associations (Original_Node (N))), |
| Relocate_Node (Left_Opnd (N))); |
| Rewrite (Next (First (Parameter_Associations (Original_Node (N)))), |
| Relocate_Node (Right_Opnd (N))); |
| else |
| Rewrite (First (Parameter_Associations (Original_Node (N))), |
| Relocate_Node (Right_Opnd (N))); |
| end if; |
| |
| Set_Parent (Original_Node (N), Parent (N)); |
| end if; |
| end Make_Call_Into_Operator; |
| |
| ------------------- |
| -- Operator_Kind -- |
| ------------------- |
| |
| function Operator_Kind |
| (Op_Name : Name_Id; |
| Is_Binary : Boolean) return Node_Kind |
| is |
| Kind : Node_Kind; |
| |
| begin |
| -- Use CASE statement or array??? |
| |
| if Is_Binary then |
| if Op_Name = Name_Op_And then |
| Kind := N_Op_And; |
| elsif Op_Name = Name_Op_Or then |
| Kind := N_Op_Or; |
| elsif Op_Name = Name_Op_Xor then |
| Kind := N_Op_Xor; |
| elsif Op_Name = Name_Op_Eq then |
| Kind := N_Op_Eq; |
| elsif Op_Name = Name_Op_Ne then |
| Kind := N_Op_Ne; |
| elsif Op_Name = Name_Op_Lt then |
| Kind := N_Op_Lt; |
| elsif Op_Name = Name_Op_Le then |
| Kind := N_Op_Le; |
| elsif Op_Name = Name_Op_Gt then |
| Kind := N_Op_Gt; |
| elsif Op_Name = Name_Op_Ge then |
| Kind := N_Op_Ge; |
| elsif Op_Name = Name_Op_Add then |
| Kind := N_Op_Add; |
| elsif Op_Name = Name_Op_Subtract then |
| Kind := N_Op_Subtract; |
| elsif Op_Name = Name_Op_Concat then |
| Kind := N_Op_Concat; |
| elsif Op_Name = Name_Op_Multiply then |
| Kind := N_Op_Multiply; |
| elsif Op_Name = Name_Op_Divide then |
| Kind := N_Op_Divide; |
| elsif Op_Name = Name_Op_Mod then |
| Kind := N_Op_Mod; |
| elsif Op_Name = Name_Op_Rem then |
| Kind := N_Op_Rem; |
| elsif Op_Name = Name_Op_Expon then |
| Kind := N_Op_Expon; |
| else |
| raise Program_Error; |
| end if; |
| |
| -- Unary operators |
| |
| else |
| if Op_Name = Name_Op_Add then |
| Kind := N_Op_Plus; |
| elsif Op_Name = Name_Op_Subtract then |
| Kind := N_Op_Minus; |
| elsif Op_Name = Name_Op_Abs then |
| Kind := N_Op_Abs; |
| elsif Op_Name = Name_Op_Not then |
| Kind := N_Op_Not; |
| else |
| raise Program_Error; |
| end if; |
| end if; |
| |
| return Kind; |
| end Operator_Kind; |
| |
| ---------------------------- |
| -- Preanalyze_And_Resolve -- |
| ---------------------------- |
| |
| procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is |
| Save_Full_Analysis : constant Boolean := Full_Analysis; |
| |
| begin |
| Full_Analysis := False; |
| Expander_Mode_Save_And_Set (False); |
| |
| -- Normally, we suppress all checks for this preanalysis. There is no |
| -- point in processing them now, since they will be applied properly |
| -- and in the proper location when the default expressions reanalyzed |
| -- and reexpanded later on. We will also have more information at that |
| -- point for possible suppression of individual checks. |
| |
| -- However, in SPARK mode, most expansion is suppressed, and this |
| -- later reanalysis and reexpansion may not occur. SPARK mode does |
| -- require the setting of checking flags for proof purposes, so we |
| -- do the SPARK preanalysis without suppressing checks. |
| |
| -- This special handling for SPARK mode is required for example in the |
| -- case of Ada 2012 constructs such as quantified expressions, which are |
| -- expanded in two separate steps. |
| |
| if GNATprove_Mode then |
| Analyze_And_Resolve (N, T); |
| else |
| Analyze_And_Resolve (N, T, Suppress => All_Checks); |
| end if; |
| |
| Expander_Mode_Restore; |
| Full_Analysis := Save_Full_Analysis; |
| end Preanalyze_And_Resolve; |
| |
| -- Version without context type |
| |
| procedure Preanalyze_And_Resolve (N : Node_Id) is |
| Save_Full_Analysis : constant Boolean := Full_Analysis; |
| |
| begin |
| Full_Analysis := False; |
| Expander_Mode_Save_And_Set (False); |
| |
| Analyze (N); |
| Resolve (N, Etype (N), Suppress => All_Checks); |
| |
| Expander_Mode_Restore; |
| Full_Analysis := Save_Full_Analysis; |
| end Preanalyze_And_Resolve; |
| |
| ---------------------------------- |
| -- Replace_Actual_Discriminants -- |
| ---------------------------------- |
| |
| procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Tsk : Node_Id := Empty; |
| |
| function Process_Discr (Nod : Node_Id) return Traverse_Result; |
| -- Comment needed??? |
| |
| ------------------- |
| -- Process_Discr -- |
| ------------------- |
| |
| function Process_Discr (Nod : Node_Id) return Traverse_Result is |
| Ent : Entity_Id; |
| |
| begin |
| if Nkind (Nod) = N_Identifier then |
| Ent := Entity (Nod); |
| |
| if Present (Ent) |
| and then Ekind (Ent) = E_Discriminant |
| then |
| Rewrite (Nod, |
| Make_Selected_Component (Loc, |
| Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc), |
| Selector_Name => Make_Identifier (Loc, Chars (Ent)))); |
| |
| Set_Etype (Nod, Etype (Ent)); |
| end if; |
| |
| end if; |
| |
| return OK; |
| end Process_Discr; |
| |
| procedure Replace_Discrs is new Traverse_Proc (Process_Discr); |
| |
| -- Start of processing for Replace_Actual_Discriminants |
| |
| begin |
| if not Expander_Active then |
| return; |
| end if; |
| |
| if Nkind (Name (N)) = N_Selected_Component then |
| Tsk := Prefix (Name (N)); |
| |
| elsif Nkind (Name (N)) = N_Indexed_Component then |
| Tsk := Prefix (Prefix (Name (N))); |
| end if; |
| |
| if No (Tsk) then |
| return; |
| else |
| Replace_Discrs (Default); |
| end if; |
| end Replace_Actual_Discriminants; |
| |
| ------------- |
| -- Resolve -- |
| ------------- |
| |
| procedure Resolve (N : Node_Id; Typ : Entity_Id) is |
| Ambiguous : Boolean := False; |
| Ctx_Type : Entity_Id := Typ; |
| Expr_Type : Entity_Id := Empty; -- prevent junk warning |
| Err_Type : Entity_Id := Empty; |
| Found : Boolean := False; |
| From_Lib : Boolean; |
| I : Interp_Index; |
| I1 : Interp_Index := 0; -- prevent junk warning |
| It : Interp; |
| It1 : Interp; |
| Seen : Entity_Id := Empty; -- prevent junk warning |
| |
| function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean; |
| -- Determine whether a node comes from a predefined library unit or |
| -- Standard. |
| |
| procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id); |
| -- Try and fix up a literal so that it matches its expected type. New |
| -- literals are manufactured if necessary to avoid cascaded errors. |
| |
| function Proper_Current_Scope return Entity_Id; |
| -- Return the current scope. Skip loop scopes created for the purpose of |
| -- quantified expression analysis since those do not appear in the tree. |
| |
| procedure Report_Ambiguous_Argument; |
| -- Additional diagnostics when an ambiguous call has an ambiguous |
| -- argument (typically a controlling actual). |
| |
| procedure Resolution_Failed; |
| -- Called when attempt at resolving current expression fails |
| |
| ------------------------------------ |
| -- Comes_From_Predefined_Lib_Unit -- |
| ------------------------------------- |
| |
| function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is |
| begin |
| return |
| Sloc (Nod) = Standard_Location |
| or else Is_Predefined_File_Name |
| (Unit_File_Name (Get_Source_Unit (Sloc (Nod)))); |
| end Comes_From_Predefined_Lib_Unit; |
| |
| -------------------- |
| -- Patch_Up_Value -- |
| -------------------- |
| |
| procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is |
| begin |
| if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then |
| Rewrite (N, |
| Make_Real_Literal (Sloc (N), |
| Realval => UR_From_Uint (Intval (N)))); |
| Set_Etype (N, Universal_Real); |
| Set_Is_Static_Expression (N); |
| |
| elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then |
| Rewrite (N, |
| Make_Integer_Literal (Sloc (N), |
| Intval => UR_To_Uint (Realval (N)))); |
| Set_Etype (N, Universal_Integer); |
| Set_Is_Static_Expression (N); |
| |
| elsif Nkind (N) = N_String_Literal |
| and then Is_Character_Type (Typ) |
| then |
| Set_Character_Literal_Name (Char_Code (Character'Pos ('A'))); |
| Rewrite (N, |
| Make_Character_Literal (Sloc (N), |
| Chars => Name_Find, |
| Char_Literal_Value => |
| UI_From_Int (Character'Pos ('A')))); |
| Set_Etype (N, Any_Character); |
| Set_Is_Static_Expression (N); |
| |
| elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then |
| Rewrite (N, |
| Make_String_Literal (Sloc (N), |
| Strval => End_String)); |
| |
| elsif Nkind (N) = N_Range then |
| Patch_Up_Value (Low_Bound (N), Typ); |
| Patch_Up_Value (High_Bound (N), Typ); |
| end if; |
| end Patch_Up_Value; |
| |
| -------------------------- |
| -- Proper_Current_Scope -- |
| -------------------------- |
| |
| function Proper_Current_Scope return Entity_Id is |
| S : Entity_Id := Current_Scope; |
| |
| begin |
| while Present (S) loop |
| |
| -- Skip a loop scope created for quantified expression analysis |
| |
| if Ekind (S) = E_Loop |
| and then Nkind (Parent (S)) = N_Quantified_Expression |
| then |
| S := Scope (S); |
| else |
| exit; |
| end if; |
| end loop; |
| |
| return S; |
| end Proper_Current_Scope; |
| |
| ------------------------------- |
| -- Report_Ambiguous_Argument -- |
| ------------------------------- |
| |
| procedure Report_Ambiguous_Argument is |
| Arg : constant Node_Id := First (Parameter_Associations (N)); |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| if Nkind (Arg) = N_Function_Call |
| and then Is_Entity_Name (Name (Arg)) |
| and then Is_Overloaded (Name (Arg)) |
| then |
| Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg)); |
| |
| -- Could use comments on what is going on here??? |
| |
| Get_First_Interp (Name (Arg), I, It); |
| while Present (It.Nam) loop |
| Error_Msg_Sloc := Sloc (It.Nam); |
| |
| if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then |
| Error_Msg_N ("interpretation (inherited) #!", Arg); |
| else |
| Error_Msg_N ("interpretation #!", Arg); |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end if; |
| end Report_Ambiguous_Argument; |
| |
| ----------------------- |
| -- Resolution_Failed -- |
| ----------------------- |
| |
| procedure Resolution_Failed is |
| begin |
| Patch_Up_Value (N, Typ); |
| Set_Etype (N, Typ); |
| Debug_A_Exit ("resolving ", N, " (done, resolution failed)"); |
| Set_Is_Overloaded (N, False); |
| |
| -- The caller will return without calling the expander, so we need |
| -- to set the analyzed flag. Note that it is fine to set Analyzed |
| -- to True even if we are in the middle of a shallow analysis, |
| -- (see the spec of sem for more details) since this is an error |
| -- situation anyway, and there is no point in repeating the |
| -- analysis later (indeed it won't work to repeat it later, since |
| -- we haven't got a clear resolution of which entity is being |
| -- referenced.) |
| |
| Set_Analyzed (N, True); |
| return; |
| end Resolution_Failed; |
| |
| -- Start of processing for Resolve |
| |
| begin |
| if N = Error then |
| return; |
| end if; |
| |
| -- Access attribute on remote subprogram cannot be used for a non-remote |
| -- access-to-subprogram type. |
| |
| if Nkind (N) = N_Attribute_Reference |
| and then Nam_In (Attribute_Name (N), Name_Access, |
| Name_Unrestricted_Access, |
| Name_Unchecked_Access) |
| and then Comes_From_Source (N) |
| and then Is_Entity_Name (Prefix (N)) |
| and then Is_Subprogram (Entity (Prefix (N))) |
| and then Is_Remote_Call_Interface (Entity (Prefix (N))) |
| and then not Is_Remote_Access_To_Subprogram_Type (Typ) |
| then |
| Error_Msg_N |
| ("prefix must statically denote a non-remote subprogram", N); |
| end if; |
| |
| From_Lib := Comes_From_Predefined_Lib_Unit (N); |
| |
| -- If the context is a Remote_Access_To_Subprogram, access attributes |
| -- must be resolved with the corresponding fat pointer. There is no need |
| -- to check for the attribute name since the return type of an |
| -- attribute is never a remote type. |
| |
| if Nkind (N) = N_Attribute_Reference |
| and then Comes_From_Source (N) |
| and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ)) |
| then |
| declare |
| Attr : constant Attribute_Id := |
| Get_Attribute_Id (Attribute_Name (N)); |
| Pref : constant Node_Id := Prefix (N); |
| Decl : Node_Id; |
| Spec : Node_Id; |
| Is_Remote : Boolean := True; |
| |
| begin |
| -- Check that Typ is a remote access-to-subprogram type |
| |
| if Is_Remote_Access_To_Subprogram_Type (Typ) then |
| |
| -- Prefix (N) must statically denote a remote subprogram |
| -- declared in a package specification. |
| |
| if Attr = Attribute_Access or else |
| Attr = Attribute_Unchecked_Access or else |
| Attr = Attribute_Unrestricted_Access |
| then |
| Decl := Unit_Declaration_Node (Entity (Pref)); |
| |
| if Nkind (Decl) = N_Subprogram_Body then |
| Spec := Corresponding_Spec (Decl); |
| |
| if not No (Spec) then |
| Decl := Unit_Declaration_Node (Spec); |
| end if; |
| end if; |
| |
| Spec := Parent (Decl); |
| |
| if not Is_Entity_Name (Prefix (N)) |
| or else Nkind (Spec) /= N_Package_Specification |
| or else |
| not Is_Remote_Call_Interface (Defining_Entity (Spec)) |
| then |
| Is_Remote := False; |
| Error_Msg_N |
| ("prefix must statically denote a remote subprogram ", |
| N); |
| end if; |
| |
| -- If we are generating code in distributed mode, perform |
| -- semantic checks against corresponding remote entities. |
| |
| if Expander_Active |
| and then Get_PCS_Name /= Name_No_DSA |
| then |
| Check_Subtype_Conformant |
| (New_Id => Entity (Prefix (N)), |
| Old_Id => Designated_Type |
| (Corresponding_Remote_Type (Typ)), |
| Err_Loc => N); |
| |
| if Is_Remote then |
| Process_Remote_AST_Attribute (N, Typ); |
| end if; |
| end if; |
| end if; |
| end if; |
| end; |
| end if; |
| |
| Debug_A_Entry ("resolving ", N); |
| |
| if Debug_Flag_V then |
| Write_Overloads (N); |
| end if; |
| |
| if Comes_From_Source (N) then |
| if Is_Fixed_Point_Type (Typ) then |
| Check_Restriction (No_Fixed_Point, N); |
| |
| elsif Is_Floating_Point_Type (Typ) |
| and then Typ /= Universal_Real |
| and then Typ /= Any_Real |
| then |
| Check_Restriction (No_Floating_Point, N); |
| end if; |
| end if; |
| |
| -- Return if already analyzed |
| |
| if Analyzed (N) then |
| Debug_A_Exit ("resolving ", N, " (done, already analyzed)"); |
| Analyze_Dimension (N); |
| return; |
| |
| -- Any case of Any_Type as the Etype value means that we had a |
| -- previous error. |
| |
| elsif Etype (N) = Any_Type then |
| Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)"); |
| return; |
| end if; |
| |
| Check_Parameterless_Call (N); |
| |
| -- The resolution of an Expression_With_Actions is determined by |
| -- its Expression. |
| |
| if Nkind (N) = N_Expression_With_Actions then |
| Resolve (Expression (N), Typ); |
| |
| Found := True; |
| Expr_Type := Etype (Expression (N)); |
| |
| -- If not overloaded, then we know the type, and all that needs doing |
| -- is to check that this type is compatible with the context. |
| |
| elsif not Is_Overloaded (N) then |
| Found := Covers (Typ, Etype (N)); |
| Expr_Type := Etype (N); |
| |
| -- In the overloaded case, we must select the interpretation that |
| -- is compatible with the context (i.e. the type passed to Resolve) |
| |
| else |
| -- Loop through possible interpretations |
| |
| Get_First_Interp (N, I, It); |
| Interp_Loop : while Present (It.Typ) loop |
| |
| if Debug_Flag_V then |
| Write_Str ("Interp: "); |
| Write_Interp (It); |
| end if; |
| |
| -- We are only interested in interpretations that are compatible |
| -- with the expected type, any other interpretations are ignored. |
| |
| if not Covers (Typ, It.Typ) then |
| if Debug_Flag_V then |
| Write_Str (" interpretation incompatible with context"); |
| Write_Eol; |
| end if; |
| |
| else |
| -- Skip the current interpretation if it is disabled by an |
| -- abstract operator. This action is performed only when the |
| -- type against which we are resolving is the same as the |
| -- type of the interpretation. |
| |
| if Ada_Version >= Ada_2005 |
| and then It.Typ = Typ |
| and then Typ /= Universal_Integer |
| and then Typ /= Universal_Real |
| and then Present (It.Abstract_Op) |
| then |
| if Debug_Flag_V then |
| Write_Line ("Skip."); |
| end if; |
| |
| goto Continue; |
| end if; |
| |
| -- First matching interpretation |
| |
| if not Found then |
| Found := True; |
| I1 := I; |
| Seen := It.Nam; |
| Expr_Type := It.Typ; |
| |
| -- Matching interpretation that is not the first, maybe an |
| -- error, but there are some cases where preference rules are |
| -- used to choose between the two possibilities. These and |
| -- some more obscure cases are handled in Disambiguate. |
| |
| else |
| -- If the current statement is part of a predefined library |
| -- unit, then all interpretations which come from user level |
| -- packages should not be considered. Check previous and |
| -- current one. |
| |
| if From_Lib then |
| if not Comes_From_Predefined_Lib_Unit (It.Nam) then |
| goto Continue; |
| |
| elsif not Comes_From_Predefined_Lib_Unit (Seen) then |
| |
| -- Previous interpretation must be discarded |
| |
| I1 := I; |
| Seen := It.Nam; |
| Expr_Type := It.Typ; |
| Set_Entity (N, Seen); |
| goto Continue; |
| end if; |
| end if; |
| |
| -- Otherwise apply further disambiguation steps |
| |
| Error_Msg_Sloc := Sloc (Seen); |
| It1 := Disambiguate (N, I1, I, Typ); |
| |
| -- Disambiguation has succeeded. Skip the remaining |
| -- interpretations. |
| |
| if It1 /= No_Interp then |
| Seen := It1.Nam; |
| Expr_Type := It1.Typ; |
| |
| while Present (It.Typ) loop |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| else |
| -- Before we issue an ambiguity complaint, check for |
| -- the case of a subprogram call where at least one |
| -- of the arguments is Any_Type, and if so, suppress |
| -- the message, since it is a cascaded error. |
| |
| if Nkind (N) in N_Subprogram_Call then |
| declare |
| A : Node_Id; |
| E : Node_Id; |
| |
| begin |
| A := First_Actual (N); |
| while Present (A) loop |
| E := A; |
| |
| if Nkind (E) = N_Parameter_Association then |
| E := Explicit_Actual_Parameter (E); |
| end if; |
| |
| if Etype (E) = Any_Type then |
| if Debug_Flag_V then |
| Write_Str ("Any_Type in call"); |
| Write_Eol; |
| end if; |
| |
| exit Interp_Loop; |
| end if; |
| |
| Next_Actual (A); |
| end loop; |
| end; |
| |
| elsif Nkind (N) in N_Binary_Op |
| and then (Etype (Left_Opnd (N)) = Any_Type |
| or else Etype (Right_Opnd (N)) = Any_Type) |
| then |
| exit Interp_Loop; |
| |
| elsif Nkind (N) in N_Unary_Op |
| and then Etype (Right_Opnd (N)) = Any_Type |
| then |
| exit Interp_Loop; |
| end if; |
| |
| -- Not that special case, so issue message using the |
| -- flag Ambiguous to control printing of the header |
| -- message only at the start of an ambiguous set. |
| |
| if not Ambiguous then |
| if Nkind (N) = N_Function_Call |
| and then Nkind (Name (N)) = N_Explicit_Dereference |
| then |
| Error_Msg_N |
| ("ambiguous expression " |
| & "(cannot resolve indirect call)!", N); |
| else |
| Error_Msg_NE -- CODEFIX |
| ("ambiguous expression (cannot resolve&)!", |
| N, It.Nam); |
| end if; |
| |
| Ambiguous := True; |
| |
| if Nkind (Parent (Seen)) = N_Full_Type_Declaration then |
| Error_Msg_N |
| ("\\possible interpretation (inherited)#!", N); |
| else |
| Error_Msg_N -- CODEFIX |
| ("\\possible interpretation#!", N); |
| end if; |
| |
| if Nkind (N) in N_Subprogram_Call |
| and then Present (Parameter_Associations (N)) |
| then |
| Report_Ambiguous_Argument; |
| end if; |
| end if; |
| |
| Error_Msg_Sloc := Sloc (It.Nam); |
| |
| -- By default, the error message refers to the candidate |
| -- interpretation. But if it is a predefined operator, it |
| -- is implicitly declared at the declaration of the type |
| -- of the operand. Recover the sloc of that declaration |
| -- for the error message. |
| |
| if Nkind (N) in N_Op |
| and then Scope (It.Nam) = Standard_Standard |
| and then not Is_Overloaded (Right_Opnd (N)) |
| and then Scope (Base_Type (Etype (Right_Opnd (N)))) /= |
| Standard_Standard |
| then |
| Err_Type := First_Subtype (Etype (Right_Opnd (N))); |
| |
| if Comes_From_Source (Err_Type) |
| and then Present (Parent (Err_Type)) |
| then |
| Error_Msg_Sloc := Sloc (Parent (Err_Type)); |
| end if; |
| |
| elsif Nkind (N) in N_Binary_Op |
| and then Scope (It.Nam) = Standard_Standard |
| and then not Is_Overloaded (Left_Opnd (N)) |
| and then Scope (Base_Type (Etype (Left_Opnd (N)))) /= |
| Standard_Standard |
| then |
| Err_Type := First_Subtype (Etype (Left_Opnd (N))); |
| |
| if Comes_From_Source (Err_Type) |
| and then Present (Parent (Err_Type)) |
| then |
| Error_Msg_Sloc := Sloc (Parent (Err_Type)); |
| end if; |
| |
| -- If this is an indirect call, use the subprogram_type |
| -- in the message, to have a meaningful location. Also |
| -- indicate if this is an inherited operation, created |
| -- by a type declaration. |
| |
| elsif Nkind (N) = N_Function_Call |
| and then Nkind (Name (N)) = N_Explicit_Dereference |
| and then Is_Type (It.Nam) |
| then |
| Err_Type := It.Nam; |
| Error_Msg_Sloc := |
| Sloc (Associated_Node_For_Itype (Err_Type)); |
| else |
| Err_Type := Empty; |
| end if; |
| |
| if Nkind (N) in N_Op |
| and then Scope (It.Nam) = Standard_Standard |
| and then Present (Err_Type) |
| then |
| -- Special-case the message for universal_fixed |
| -- operators, which are not declared with the type |
| -- of the operand, but appear forever in Standard. |
| |
| if It.Typ = Universal_Fixed |
| and then Scope (It.Nam) = Standard_Standard |
| then |
| Error_Msg_N |
| ("\\possible interpretation as universal_fixed " |
| & "operation (RM 4.5.5 (19))", N); |
| else |
| Error_Msg_N |
| ("\\possible interpretation (predefined)#!", N); |
| end if; |
| |
| elsif |
| Nkind (Parent (It.Nam)) = N_Full_Type_Declaration |
| then |
| Error_Msg_N |
| ("\\possible interpretation (inherited)#!", N); |
| else |
| Error_Msg_N -- CODEFIX |
| ("\\possible interpretation#!", N); |
| end if; |
| |
| end if; |
| end if; |
| |
| -- We have a matching interpretation, Expr_Type is the type |
| -- from this interpretation, and Seen is the entity. |
| |
| -- For an operator, just set the entity name. The type will be |
| -- set by the specific operator resolution routine. |
| |
| if Nkind (N) in N_Op then |
| Set_Entity (N, Seen); |
| Generate_Reference (Seen, N); |
| |
| elsif Nkind (N) = N_Case_Expression then |
| Set_Etype (N, Expr_Type); |
| |
| elsif Nkind (N) = N_Character_Literal then |
| Set_Etype (N, Expr_Type); |
| |
| elsif Nkind (N) = N_If_Expression then |
| Set_Etype (N, Expr_Type); |
| |
| -- AI05-0139-2: Expression is overloaded because type has |
| -- implicit dereference. If type matches context, no implicit |
| -- dereference is involved. |
| |
| elsif Has_Implicit_Dereference (Expr_Type) then |
| Set_Etype (N, Expr_Type); |
| Set_Is_Overloaded (N, False); |
| exit Interp_Loop; |
| |
| elsif Is_Overloaded (N) |
| and then Present (It.Nam) |
| and then Ekind (It.Nam) = E_Discriminant |
| and then Has_Implicit_Dereference (It.Nam) |
| then |
| -- If the node is a general indexing, the dereference is |
| -- is inserted when resolving the rewritten form, else |
| -- insert it now. |
| |
| if Nkind (N) /= N_Indexed_Component |
| or else No (Generalized_Indexing (N)) |
| then |
| Build_Explicit_Dereference (N, It.Nam); |
| end if; |
| |
| -- For an explicit dereference, attribute reference, range, |
| -- short-circuit form (which is not an operator node), or call |
| -- with a name that is an explicit dereference, there is |
| -- nothing to be done at this point. |
| |
| elsif Nkind_In (N, N_Explicit_Dereference, |
| N_Attribute_Reference, |
| N_And_Then, |
| N_Indexed_Component, |
| N_Or_Else, |
| N_Range, |
| N_Selected_Component, |
| N_Slice) |
| or else Nkind (Name (N)) = N_Explicit_Dereference |
| then |
| null; |
| |
| -- For procedure or function calls, set the type of the name, |
| -- and also the entity pointer for the prefix. |
| |
| elsif Nkind (N) in N_Subprogram_Call |
| and then Is_Entity_Name (Name (N)) |
| then |
| Set_Etype (Name (N), Expr_Type); |
| Set_Entity (Name (N), Seen); |
| Generate_Reference (Seen, Name (N)); |
| |
| elsif Nkind (N) = N_Function_Call |
| and then Nkind (Name (N)) = N_Selected_Component |
| then |
| Set_Etype (Name (N), Expr_Type); |
| Set_Entity (Selector_Name (Name (N)), Seen); |
| Generate_Reference (Seen, Selector_Name (Name (N))); |
| |
| -- For all other cases, just set the type of the Name |
| |
| else |
| Set_Etype (Name (N), Expr_Type); |
| end if; |
| |
| end if; |
| |
| <<Continue>> |
| |
| -- Move to next interpretation |
| |
| exit Interp_Loop when No (It.Typ); |
| |
| Get_Next_Interp (I, It); |
| end loop Interp_Loop; |
| end if; |
| |
| -- At this stage Found indicates whether or not an acceptable |
| -- interpretation exists. If not, then we have an error, except that if |
| -- the context is Any_Type as a result of some other error, then we |
| -- suppress the error report. |
| |
| if not Found then |
| if Typ /= Any_Type then |
| |
| -- If type we are looking for is Void, then this is the procedure |
| -- call case, and the error is simply that what we gave is not a |
| -- procedure name (we think of procedure calls as expressions with |
| -- types internally, but the user doesn't think of them this way). |
| |
| if Typ = Standard_Void_Type then |
| |
| -- Special case message if function used as a procedure |
| |
| if Nkind (N) = N_Procedure_Call_Statement |
| and then Is_Entity_Name (Name (N)) |
| and then Ekind (Entity (Name (N))) = E_Function |
| then |
| Error_Msg_NE |
| ("cannot use function & in a procedure call", |
| Name (N), Entity (Name (N))); |
| |
| -- Otherwise give general message (not clear what cases this |
| -- covers, but no harm in providing for them). |
| |
| else |
| Error_Msg_N ("expect procedure name in procedure call", N); |
| end if; |
| |
| Found := True; |
| |
| -- Otherwise we do have a subexpression with the wrong type |
| |
| -- Check for the case of an allocator which uses an access type |
| -- instead of the designated type. This is a common error and we |
| -- specialize the message, posting an error on the operand of the |
| -- allocator, complaining that we expected the designated type of |
| -- the allocator. |
| |
| elsif Nkind (N) = N_Allocator |
| and then Ekind (Typ) in Access_Kind |
| and then Ekind (Etype (N)) in Access_Kind |
| and then Designated_Type (Etype (N)) = Typ |
| then |
| Wrong_Type (Expression (N), Designated_Type (Typ)); |
| Found := True; |
| |
| -- Check for view mismatch on Null in instances, for which the |
| -- view-swapping mechanism has no identifier. |
| |
| elsif (In_Instance or else In_Inlined_Body) |
| and then (Nkind (N) = N_Null) |
| and then Is_Private_Type (Typ) |
| and then Is_Access_Type (Full_View (Typ)) |
| then |
| Resolve (N, Full_View (Typ)); |
| Set_Etype (N, Typ); |
| return; |
| |
| -- Check for an aggregate. Sometimes we can get bogus aggregates |
| -- from misuse of parentheses, and we are about to complain about |
| -- the aggregate without even looking inside it. |
| |
| -- Instead, if we have an aggregate of type Any_Composite, then |
| -- analyze and resolve the component fields, and then only issue |
| -- another message if we get no errors doing this (otherwise |
| -- assume that the errors in the aggregate caused the problem). |
| |
| elsif Nkind (N) = N_Aggregate |
| and then Etype (N) = Any_Composite |
| then |
| -- Disable expansion in any case. If there is a type mismatch |
| -- it may be fatal to try to expand the aggregate. The flag |
| -- would otherwise be set to false when the error is posted. |
| |
| Expander_Active := False; |
| |
| declare |
| procedure Check_Aggr (Aggr : Node_Id); |
| -- Check one aggregate, and set Found to True if we have a |
| -- definite error in any of its elements |
| |
| procedure Check_Elmt (Aelmt : Node_Id); |
| -- Check one element of aggregate and set Found to True if |
| -- we definitely have an error in the element. |
| |
| ---------------- |
| -- Check_Aggr -- |
| ---------------- |
| |
| procedure Check_Aggr (Aggr : Node_Id) is |
| Elmt : Node_Id; |
| |
| begin |
| if Present (Expressions (Aggr)) then |
| Elmt := First (Expressions (Aggr)); |
| while Present (Elmt) loop |
| Check_Elmt (Elmt); |
| Next (Elmt); |
| end loop; |
| end if; |
| |
| if Present (Component_Associations (Aggr)) then |
| Elmt := First (Component_Associations (Aggr)); |
| while Present (Elmt) loop |
| |
| -- If this is a default-initialized component, then |
| -- there is nothing to check. The box will be |
| -- replaced by the appropriate call during late |
| -- expansion. |
| |
| if not Box_Present (Elmt) then |
| Check_Elmt (Expression (Elmt)); |
| end if; |
| |
| Next (Elmt); |
| end loop; |
| end if; |
| end Check_Aggr; |
| |
| ---------------- |
| -- Check_Elmt -- |
| ---------------- |
| |
| procedure Check_Elmt (Aelmt : Node_Id) is |
| begin |
| -- If we have a nested aggregate, go inside it (to |
| -- attempt a naked analyze-resolve of the aggregate can |
| -- cause undesirable cascaded errors). Do not resolve |
| -- expression if it needs a type from context, as for |
| -- integer * fixed expression. |
| |
| if Nkind (Aelmt) = N_Aggregate then |
| Check_Aggr (Aelmt); |
| |
| else |
| Analyze (Aelmt); |
| |
| if not Is_Overloaded (Aelmt) |
| and then Etype (Aelmt) /= Any_Fixed |
| then |
| Resolve (Aelmt); |
| end if; |
| |
| if Etype (Aelmt) = Any_Type then |
| Found := True; |
| end if; |
| end if; |
| end Check_Elmt; |
| |
| begin |
| Check_Aggr (N); |
| end; |
| end if; |
| |
| -- Looks like we have a type error, but check for special case |
| -- of Address wanted, integer found, with the configuration pragma |
| -- Allow_Integer_Address active. If we have this case, introduce |
| -- an unchecked conversion to allow the integer expression to be |
| -- treated as an Address. The reverse case of integer wanted, |
| -- Address found, is treated in an analogous manner. |
| |
| if Address_Integer_Convert_OK (Typ, Etype (N)) then |
| Rewrite (N, Unchecked_Convert_To (Typ, Relocate_Node (N))); |
| Analyze_And_Resolve (N, Typ); |
| return; |
| end if; |
| |
| -- That special Allow_Integer_Address check did not appply, so we |
| -- have a real type error. If an error message was issued already, |
| -- Found got reset to True, so if it's still False, issue standard |
| -- Wrong_Type message. |
| |
| if not Found then |
| if Is_Overloaded (N) and then Nkind (N) = N_Function_Call then |
| declare |
| Subp_Name : Node_Id; |
| |
| begin |
| if Is_Entity_Name (Name (N)) then |
| Subp_Name := Name (N); |
| |
| elsif Nkind (Name (N)) = N_Selected_Component then |
| |
| -- Protected operation: retrieve operation name |
| |
| Subp_Name := Selector_Name (Name (N)); |
| |
| else |
| raise Program_Error; |
| end if; |
| |
| Error_Msg_Node_2 := Typ; |
| Error_Msg_NE |
| ("no visible interpretation of& " |
| & "matches expected type&", N, Subp_Name); |
| end; |
| |
| if All_Errors_Mode then |
| declare |
| Index : Interp_Index; |
| It : Interp; |
| |
| begin |
| Error_Msg_N ("\\possible interpretations:", N); |
| |
| Get_First_Interp (Name (N), Index, It); |
| while Present (It.Nam) loop |
| Error_Msg_Sloc := Sloc (It.Nam); |
| Error_Msg_Node_2 := It.Nam; |
| Error_Msg_NE |
| ("\\ type& for & declared#", N, It.Typ); |
| Get_Next_Interp (Index, It); |
| end loop; |
| end; |
| |
| else |
| Error_Msg_N ("\use -gnatf for details", N); |
| end if; |
| |
| else |
| Wrong_Type (N, Typ); |
| end if; |
| end if; |
| end if; |
| |
| Resolution_Failed; |
| return; |
| |
| -- Test if we have more than one interpretation for the context |
| |
| elsif Ambiguous then |
| Resolution_Failed; |
| return; |
| |
| -- Only one intepretation |
| |
| else |
| -- In Ada 2005, if we have something like "X : T := 2 + 2;", where |
| -- the "+" on T is abstract, and the operands are of universal type, |
| -- the above code will have (incorrectly) resolved the "+" to the |
| -- universal one in Standard. Therefore check for this case and give |
| -- an error. We can't do this earlier, because it would cause legal |
| -- cases to get errors (when some other type has an abstract "+"). |
| |
| if Ada_Version >= Ada_2005 |
| and then Nkind (N) in N_Op |
| and then Is_Overloaded (N) |
| and then Is_Universal_Numeric_Type (Etype (Entity (N))) |
| then |
| Get_First_Interp (N, I, It); |
| while Present (It.Typ) loop |
| if Present (It.Abstract_Op) and then |
| Etype (It.Abstract_Op) = Typ |
| then |
| Error_Msg_NE |
| ("cannot call abstract subprogram &!", N, It.Abstract_Op); |
| return; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end if; |
| |
| -- Here we have an acceptable interpretation for the context |
| |
| -- Propagate type information and normalize tree for various |
| -- predefined operations. If the context only imposes a class of |
| -- types, rather than a specific type, propagate the actual type |
| -- downward. |
| |
| if Typ = Any_Integer or else |
| Typ = Any_Boolean or else |
| Typ = Any_Modular or else |
| Typ = Any_Real or else |
| Typ = Any_Discrete |
| then |
| Ctx_Type := Expr_Type; |
| |
| -- Any_Fixed is legal in a real context only if a specific fixed- |
| -- point type is imposed. If Norman Cohen can be confused by this, |
| -- it deserves a separate message. |
| |
| if Typ = Any_Real |
| and then Expr_Type = Any_Fixed |
| then |
| Error_Msg_N ("illegal context for mixed mode operation", N); |
| Set_Etype (N, Universal_Real); |
| Ctx_Type := Universal_Real; |
| end if; |
| end if; |
| |
| -- A user-defined operator is transformed into a function call at |
| -- this point, so that further processing knows that operators are |
| -- really operators (i.e. are predefined operators). User-defined |
| -- operators that are intrinsic are just renamings of the predefined |
| -- ones, and need not be turned into calls either, but if they rename |
| -- a different operator, we must transform the node accordingly. |
| -- Instantiations of Unchecked_Conversion are intrinsic but are |
| -- treated as functions, even if given an operator designator. |
| |
| if Nkind (N) in N_Op |
| and then Present (Entity (N)) |
| and then Ekind (Entity (N)) /= E_Operator |
| then |
| |
| if not Is_Predefined_Op (Entity (N)) then |
| Rewrite_Operator_As_Call (N, Entity (N)); |
| |
| elsif Present (Alias (Entity (N))) |
| and then |
| Nkind (Parent (Parent (Entity (N)))) = |
| N_Subprogram_Renaming_Declaration |
| then |
| Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ); |
| |
| -- If the node is rewritten, it will be fully resolved in |
| -- Rewrite_Renamed_Operator. |
| |
| if Analyzed (N) then |
| return; |
| end if; |
| end if; |
| end if; |
| |
| case N_Subexpr'(Nkind (N)) is |
| |
| when N_Aggregate => Resolve_Aggregate (N, Ctx_Type); |
| |
| when N_Allocator => Resolve_Allocator (N, Ctx_Type); |
| |
| when N_Short_Circuit |
| => Resolve_Short_Circuit (N, Ctx_Type); |
| |
| when N_Attribute_Reference |
| => Resolve_Attribute (N, Ctx_Type); |
| |
| when N_Case_Expression |
| => Resolve_Case_Expression (N, Ctx_Type); |
| |
| when N_Character_Literal |
| => Resolve_Character_Literal (N, Ctx_Type); |
| |
| when N_Expanded_Name |
| => Resolve_Entity_Name (N, Ctx_Type); |
| |
| when N_Explicit_Dereference |
| => Resolve_Explicit_Dereference (N, Ctx_Type); |
| |
| when N_Expression_With_Actions |
| => Resolve_Expression_With_Actions (N, Ctx_Type); |
| |
| when N_Extension_Aggregate |
| => Resolve_Extension_Aggregate (N, Ctx_Type); |
| |
| when N_Function_Call |
| => Resolve_Call (N, Ctx_Type); |
| |
| when N_Identifier |
| => Resolve_Entity_Name (N, Ctx_Type); |
| |
| when N_If_Expression |
| => Resolve_If_Expression (N, Ctx_Type); |
| |
| when N_Indexed_Component |
| => Resolve_Indexed_Component (N, Ctx_Type); |
| |
| when N_Integer_Literal |
| => Resolve_Integer_Literal (N, Ctx_Type); |
| |
| when N_Membership_Test |
| => Resolve_Membership_Op (N, Ctx_Type); |
| |
| when N_Null => Resolve_Null (N, Ctx_Type); |
| |
| when N_Op_And | N_Op_Or | N_Op_Xor |
| => Resolve_Logical_Op (N, Ctx_Type); |
| |
| when N_Op_Eq | N_Op_Ne |
| => Resolve_Equality_Op (N, Ctx_Type); |
| |
| when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge |
| => Resolve_Comparison_Op (N, Ctx_Type); |
| |
| when N_Op_Not => Resolve_Op_Not (N, Ctx_Type); |
| |
| when N_Op_Add | N_Op_Subtract | N_Op_Multiply | |
| N_Op_Divide | N_Op_Mod | N_Op_Rem |
| |
| => Resolve_Arithmetic_Op (N, Ctx_Type); |
| |
| when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type); |
| |
| when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type); |
| |
| when N_Op_Plus | N_Op_Minus | N_Op_Abs |
| => Resolve_Unary_Op (N, Ctx_Type); |
| |
| when N_Op_Shift => Resolve_Shift (N, Ctx_Type); |
| |
| when N_Procedure_Call_Statement |
| => Resolve_Call (N, Ctx_Type); |
| |
| when N_Operator_Symbol |
| => Resolve_Operator_Symbol (N, Ctx_Type); |
| |
| when N_Qualified_Expression |
| => Resolve_Qualified_Expression (N, Ctx_Type); |
| |
| -- Why is the following null, needs a comment ??? |
| |
| when N_Quantified_Expression |
| => null; |
| |
| when N_Raise_Expression |
| => Resolve_Raise_Expression (N, Ctx_Type); |
| |
| when N_Raise_xxx_Error |
| => Set_Etype (N, Ctx_Type); |
| |
| when N_Range => Resolve_Range (N, Ctx_Type); |
| |
| when N_Real_Literal |
| => Resolve_Real_Literal (N, Ctx_Type); |
| |
| when N_Reference => Resolve_Reference (N, Ctx_Type); |
| |
| when N_Selected_Component |
| => Resolve_Selected_Component (N, Ctx_Type); |
| |
| when N_Slice => Resolve_Slice (N, Ctx_Type); |
| |
| when N_String_Literal |
| => Resolve_String_Literal (N, Ctx_Type); |
| |
| when N_Type_Conversion |
| => Resolve_Type_Conversion (N, Ctx_Type); |
| |
| when N_Unchecked_Expression => |
| Resolve_Unchecked_Expression (N, Ctx_Type); |
| |
| when N_Unchecked_Type_Conversion => |
| Resolve_Unchecked_Type_Conversion (N, Ctx_Type); |
| end case; |
| |
| -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an |
| -- expression of an anonymous access type that occurs in the context |
| -- of a named general access type, except when the expression is that |
| -- of a membership test. This ensures proper legality checking in |
| -- terms of allowed conversions (expressions that would be illegal to |
| -- convert implicitly are allowed in membership tests). |
| |
| if Ada_Version >= Ada_2012 |
| and then Ekind (Ctx_Type) = E_General_Access_Type |
| and then Ekind (Etype (N)) = E_Anonymous_Access_Type |
| and then Nkind (Parent (N)) not in N_Membership_Test |
| then |
| Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N))); |
| Analyze_And_Resolve (N, Ctx_Type); |
| end if; |
| |
| -- If the subexpression was replaced by a non-subexpression, then |
| -- all we do is to expand it. The only legitimate case we know of |
| -- is converting procedure call statement to entry call statements, |
| -- but there may be others, so we are making this test general. |
| |
| if Nkind (N) not in N_Subexpr then |
| Debug_A_Exit ("resolving ", N, " (done)"); |
| Expand (N); |
| return; |
| end if; |
| |
| -- The expression is definitely NOT overloaded at this point, so |
| -- we reset the Is_Overloaded flag to avoid any confusion when |
| -- reanalyzing the node. |
| |
| Set_Is_Overloaded (N, False); |
| |
| -- Freeze expression type, entity if it is a name, and designated |
| -- type if it is an allocator (RM 13.14(10,11,13)). |
| |
| -- Now that the resolution of the type of the node is complete, and |
| -- we did not detect an error, we can expand this node. We skip the |
| -- expand call if we are in a default expression, see section |
| -- "Handling of Default Expressions" in Sem spec. |
| |
| Debug_A_Exit ("resolving ", N, " (done)"); |
| |
| -- We unconditionally freeze the expression, even if we are in |
| -- default expression mode (the Freeze_Expression routine tests this |
| -- flag and only freezes static types if it is set). |
| |
| -- Ada 2012 (AI05-177): Expression functions do not freeze. Only |
| -- their use (in an expanded call) freezes. |
| |
| if Ekind (Proper_Current_Scope) /= E_Function |
| or else Nkind (Original_Node (Unit_Declaration_Node |
| (Proper_Current_Scope))) /= N_Expression_Function |
| then |
| Freeze_Expression (N); |
| end if; |
| |
| -- Now we can do the expansion |
| |
| Expand (N); |
| end if; |
| end Resolve; |
| |
| ------------- |
| -- Resolve -- |
| ------------- |
| |
| -- Version with check(s) suppressed |
| |
| procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is |
| begin |
| if Suppress = All_Checks then |
| declare |
| Sva : constant Suppress_Array := Scope_Suppress.Suppress; |
| begin |
| Scope_Suppress.Suppress := (others => True); |
| Resolve (N, Typ); |
| Scope_Suppress.Suppress := Sva; |
| end; |
| |
| else |
| declare |
| Svg : constant Boolean := Scope_Suppress.Suppress (Suppress); |
| begin |
| Scope_Suppress.Suppress (Suppress) := True; |
| Resolve (N, Typ); |
| Scope_Suppress.Suppress (Suppress) := Svg; |
| end; |
| end if; |
| end Resolve; |
| |
| ------------- |
| -- Resolve -- |
| ------------- |
| |
| -- Version with implicit type |
| |
| procedure Resolve (N : Node_Id) is |
| begin |
| Resolve (N, Etype (N)); |
| end Resolve; |
| |
| --------------------- |
| -- Resolve_Actuals -- |
| --------------------- |
| |
| procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| A : Node_Id; |
| A_Id : Entity_Id; |
| A_Typ : Entity_Id; |
| F : Entity_Id; |
| F_Typ : Entity_Id; |
| Prev : Node_Id := Empty; |
| Orig_A : Node_Id; |
| |
| procedure Check_Argument_Order; |
| -- Performs a check for the case where the actuals are all simple |
| -- identifiers that correspond to the formal names, but in the wrong |
| -- order, which is considered suspicious and cause for a warning. |
| |
| procedure Check_Prefixed_Call; |
| -- If the original node is an overloaded call in prefix notation, |
| -- insert an 'Access or a dereference as needed over the first actual. |
| -- Try_Object_Operation has already verified that there is a valid |
| -- interpretation, but the form of the actual can only be determined |
| -- once the primitive operation is identified. |
| |
| procedure Insert_Default; |
| -- If the actual is missing in a call, insert in the actuals list |
| -- an instance of the default expression. The insertion is always |
| -- a named association. |
| |
| procedure Property_Error |
| (Var : Node_Id; |
| Var_Id : Entity_Id; |
| Prop_Nam : Name_Id); |
| -- Emit an error concerning variable Var with entity Var_Id that has |
| -- enabled property Prop_Nam when it acts as an actual parameter in a |
| -- call and the corresponding formal parameter is of mode IN. |
| |
| function Same_Ancestor (T1, T2 : Entity_Id) return Boolean; |
| -- Check whether T1 and T2, or their full views, are derived from a |
| -- common type. Used to enforce the restrictions on array conversions |
| -- of AI95-00246. |
| |
| function Static_Concatenation (N : Node_Id) return Boolean; |
| -- Predicate to determine whether an actual that is a concatenation |
| -- will be evaluated statically and does not need a transient scope. |
| -- This must be determined before the actual is resolved and expanded |
| -- because if needed the transient scope must be introduced earlier. |
| |
| -------------------------- |
| -- Check_Argument_Order -- |
| -------------------------- |
| |
| procedure Check_Argument_Order is |
| begin |
| -- Nothing to do if no parameters, or original node is neither a |
| -- function call nor a procedure call statement (happens in the |
| -- operator-transformed-to-function call case), or the call does |
| -- not come from source, or this warning is off. |
| |
| if not Warn_On_Parameter_Order |
| or else No (Parameter_Associations (N)) |
| or else Nkind (Original_Node (N)) not in N_Subprogram_Call |
| or else not Comes_From_Source (N) |
| then |
| return; |
| end if; |
| |
| declare |
| Nargs : constant Nat := List_Length (Parameter_Associations (N)); |
| |
| begin |
| -- Nothing to do if only one parameter |
| |
| if Nargs < 2 then |
| return; |
| end if; |
| |
| -- Here if at least two arguments |
| |
| declare |
| Actuals : array (1 .. Nargs) of Node_Id; |
| Actual : Node_Id; |
| Formal : Node_Id; |
| |
| Wrong_Order : Boolean := False; |
| -- Set True if an out of order case is found |
| |
| begin |
| -- Collect identifier names of actuals, fail if any actual is |
| -- not a simple identifier, and record max length of name. |
| |
| Actual := First (Parameter_Associations (N)); |
| for J in Actuals'Range loop |
| if Nkind (Actual) /= N_Identifier then |
| return; |
| else |
| Actuals (J) := Actual; |
| Next (Actual); |
| end if; |
| end loop; |
| |
| -- If we got this far, all actuals are identifiers and the list |
| -- of their names is stored in the Actuals array. |
| |
| Formal := First_Formal (Nam); |
| for J in Actuals'Range loop |
| |
| -- If we ran out of formals, that's odd, probably an error |
| -- which will be detected elsewhere, but abandon the search. |
| |
| if No (Formal) then |
| return; |
| end if; |
| |
| -- If name matches and is in order OK |
| |
| if Chars (Formal) = Chars (Actuals (J)) then |
| null; |
| |
| else |
| -- If no match, see if it is elsewhere in list and if so |
| -- flag potential wrong order if type is compatible. |
| |
| for K in Actuals'Range loop |
| if Chars (Formal) = Chars (Actuals (K)) |
| and then |
| Has_Compatible_Type (Actuals (K), Etype (Formal)) |
| then |
| Wrong_Order := True; |
| goto Continue; |
| end if; |
| end loop; |
| |
| -- No match |
| |
| return; |
| end if; |
| |
| <<Continue>> Next_Formal (Formal); |
| end loop; |
| |
| -- If Formals left over, also probably an error, skip warning |
| |
| if Present (Formal) then |
| return; |
| end if; |
| |
| -- Here we give the warning if something was out of order |
| |
| if Wrong_Order then |
| Error_Msg_N |
| ("?P?actuals for this call may be in wrong order", N); |
| end if; |
| end; |
| end; |
| end Check_Argument_Order; |
| |
| ------------------------- |
| -- Check_Prefixed_Call -- |
| ------------------------- |
| |
| procedure Check_Prefixed_Call is |
| Act : constant Node_Id := First_Actual (N); |
| A_Type : constant Entity_Id := Etype (Act); |
| F_Type : constant Entity_Id := Etype (First_Formal (Nam)); |
| Orig : constant Node_Id := Original_Node (N); |
| New_A : Node_Id; |
| |
| begin |
| -- Check whether the call is a prefixed call, with or without |
| -- additional actuals. |
| |
| if Nkind (Orig) = N_Selected_Component |
| or else |
| (Nkind (Orig) = N_Indexed_Component |
| and then Nkind (Prefix (Orig)) = N_Selected_Component |
| and then Is_Entity_Name (Prefix (Prefix (Orig))) |
| and then Is_Entity_Name (Act) |
| and then Chars (Act) = Chars (Prefix (Prefix (Orig)))) |
| then |
| if Is_Access_Type (A_Type) |
| and then not Is_Access_Type (F_Type) |
| then |
| -- Introduce dereference on object in prefix |
| |
| New_A := |
| Make_Explicit_Dereference (Sloc (Act), |
| Prefix => Relocate_Node (Act)); |
| Rewrite (Act, New_A); |
| Analyze (Act); |
| |
| elsif Is_Access_Type (F_Type) |
| and then not Is_Access_Type (A_Type) |
| then |
| -- Introduce an implicit 'Access in prefix |
| |
| if not Is_Aliased_View (Act) then |
| Error_Msg_NE |
| ("object in prefixed call to& must be aliased" |
| & " (RM-2005 4.3.1 (13))", |
| Prefix (Act), Nam); |
| end if; |
| |
| Rewrite (Act, |
| Make_Attribute_Reference (Loc, |
| Attribute_Name => Name_Access, |
| Prefix => Relocate_Node (Act))); |
| end if; |
| |
| Analyze (Act); |
| end if; |
| end Check_Prefixed_Call; |
| |
| -------------------- |
| -- Insert_Default -- |
| -------------------- |
| |
| procedure Insert_Default is |
| Actval : Node_Id; |
| Assoc : Node_Id; |
| |
| begin |
| -- Missing argument in call, nothing to insert |
| |
| if No (Default_Value (F)) then |
| return; |
| |
| else |
| -- Note that we do a full New_Copy_Tree, so that any associated |
| -- Itypes are properly copied. This may not be needed any more, |
| -- but it does no harm as a safety measure. Defaults of a generic |
| -- formal may be out of bounds of the corresponding actual (see |
| -- cc1311b) and an additional check may be required. |
| |
| Actval := |
| New_Copy_Tree |
| (Default_Value (F), |
| New_Scope => Current_Scope, |
| New_Sloc => Loc); |
| |
| if Is_Concurrent_Type (Scope (Nam)) |
| and then Has_Discriminants (Scope (Nam)) |
| then |
| Replace_Actual_Discriminants (N, Actval); |
| end if; |
| |
| if Is_Overloadable (Nam) |
| and then Present (Alias (Nam)) |
| then |
| if Base_Type (Etype (F)) /= Base_Type (Etype (Actval)) |
| and then not Is_Tagged_Type (Etype (F)) |
| then |
| -- If default is a real literal, do not introduce a |
| -- conversion whose effect may depend on the run-time |
| -- size of universal real. |
| |
| if Nkind (Actval) = N_Real_Literal then |
| Set_Etype (Actval, Base_Type (Etype (F))); |
| else |
| Actval := Unchecked_Convert_To (Etype (F), Actval); |
| end if; |
| end if; |
| |
| if Is_Scalar_Type (Etype (F)) then |
| Enable_Range_Check (Actval); |
| end if; |
| |
| Set_Parent (Actval, N); |
| |
| -- Resolve aggregates with their base type, to avoid scope |
| -- anomalies: the subtype was first built in the subprogram |
| -- declaration, and the current call may be nested. |
| |
| if Nkind (Actval) = N_Aggregate then |
| Analyze_And_Resolve (Actval, Etype (F)); |
| else |
| Analyze_And_Resolve (Actval, Etype (Actval)); |
| end if; |
| |
| else |
| Set_Parent (Actval, N); |
| |
| -- See note above concerning aggregates |
| |
| if Nkind (Actval) = N_Aggregate |
| and then Has_Discriminants (Etype (Actval)) |
| then |
| Analyze_And_Resolve (Actval, Base_Type (Etype (Actval))); |
| |
| -- Resolve entities with their own type, which may differ from |
| -- the type of a reference in a generic context (the view |
| -- swapping mechanism did not anticipate the re-analysis of |
| -- default values in calls). |
| |
| elsif Is_Entity_Name (Actval) then |
| Analyze_And_Resolve (Actval, Etype (Entity (Actval))); |
| |
| else |
| Analyze_And_Resolve (Actval, Etype (Actval)); |
| end if; |
| end if; |
| |
| -- If default is a tag indeterminate function call, propagate tag |
| -- to obtain proper dispatching. |
| |
| if Is_Controlling_Formal (F) |
| and then Nkind (Default_Value (F)) = N_Function_Call |
| then |
| Set_Is_Controlling_Actual (Actval); |
| end if; |
| |
| end if; |
| |
| -- If the default expression raises constraint error, then just |
| -- silently replace it with an N_Raise_Constraint_Error node, since |
| -- we already gave the warning on the subprogram spec. If node is |
| -- already a Raise_Constraint_Error leave as is, to prevent loops in |
| -- the warnings removal machinery. |
| |
| if Raises_Constraint_Error (Actval) |
| and then Nkind (Actval) /= N_Raise_Constraint_Error |
| then |
| Rewrite (Actval, |
| Make_Raise_Constraint_Error (Loc, |
| Reason => CE_Range_Check_Failed)); |
| Set_Raises_Constraint_Error (Actval); |
| Set_Etype (Actval, Etype (F)); |
| end if; |
| |
| Assoc := |
| Make_Parameter_Association (Loc, |
| Explicit_Actual_Parameter => Actval, |
| Selector_Name => Make_Identifier (Loc, Chars (F))); |
| |
| -- Case of insertion is first named actual |
| |
| if No (Prev) or else |
| Nkind (Parent (Prev)) /= N_Parameter_Association |
| then |
| Set_Next_Named_Actual (Assoc, First_Named_Actual (N)); |
| Set_First_Named_Actual (N, Actval); |
| |
| if No (Prev) then |
| if No (Parameter_Associations (N)) then |
| Set_Parameter_Associations (N, New_List (Assoc)); |
| else |
| Append (Assoc, Parameter_Associations (N)); |
| end if; |
| |
| else |
| Insert_After (Prev, Assoc); |
| end if; |
| |
| -- Case of insertion is not first named actual |
| |
| else |
| Set_Next_Named_Actual |
| (Assoc, Next_Named_Actual (Parent (Prev))); |
| Set_Next_Named_Actual (Parent (Prev), Actval); |
| Append (Assoc, Parameter_Associations (N)); |
| end if; |
| |
| Mark_Rewrite_Insertion (Assoc); |
| Mark_Rewrite_Insertion (Actval); |
| |
| Prev := Actval; |
| end Insert_Default; |
| |
| -------------------- |
| -- Property_Error -- |
| -------------------- |
| |
| procedure Property_Error |
| (Var : Node_Id; |
| Var_Id : Entity_Id; |
| Prop_Nam : Name_Id) |
| is |
| begin |
| Error_Msg_Name_1 := Prop_Nam; |
| Error_Msg_NE |
| ("external variable & with enabled property % cannot appear as " |
| & "actual in procedure call (SPARK RM 7.1.3(11))", Var, Var_Id); |
| Error_Msg_N ("\\corresponding formal parameter has mode In", Var); |
| end Property_Error; |
| |
| ------------------- |
| -- Same_Ancestor -- |
| ------------------- |
| |
| function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is |
| FT1 : Entity_Id := T1; |
| FT2 : Entity_Id := T2; |
| |
| begin |
| if Is_Private_Type (T1) |
| and then Present (Full_View (T1)) |
| then |
| FT1 := Full_View (T1); |
| end if; |
| |
| if Is_Private_Type (T2) |
| and then Present (Full_View (T2)) |
| then |
| FT2 := Full_View (T2); |
| end if; |
| |
| return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2)); |
| end Same_Ancestor; |
| |
| -------------------------- |
| -- Static_Concatenation -- |
| -------------------------- |
| |
| function Static_Concatenation (N : Node_Id) return Boolean is |
| begin |
| case Nkind (N) is |
| when N_String_Literal => |
| return True; |
| |
| when N_Op_Concat => |
| |
| -- Concatenation is static when both operands are static and |
| -- the concatenation operator is a predefined one. |
| |
| return Scope (Entity (N)) = Standard_Standard |
| and then |
| Static_Concatenation (Left_Opnd (N)) |
| and then |
| Static_Concatenation (Right_Opnd (N)); |
| |
| when others => |
| if Is_Entity_Name (N) then |
| declare |
| Ent : constant Entity_Id := Entity (N); |
| begin |
| return Ekind (Ent) = E_Constant |
| and then Present (Constant_Value (Ent)) |
| and then |
| Is_Static_Expression (Constant_Value (Ent)); |
| end; |
| |
| else |
| return False; |
| end if; |
| end case; |
| end Static_Concatenation; |
| |
| -- Start of processing for Resolve_Actuals |
| |
| begin |
| Check_Argument_Order; |
| Check_Function_Writable_Actuals (N); |
| |
| if Present (First_Actual (N)) then |
| Check_Prefixed_Call; |
| end if; |
| |
| A := First_Actual (N); |
| F := First_Formal (Nam); |
| while Present (F) loop |
| if No (A) and then Needs_No_Actuals (Nam) then |
| null; |
| |
| -- If we have an error in any actual or formal, indicated by a type |
| -- of Any_Type, then abandon resolution attempt, and set result type |
| -- to Any_Type. Skip this if the actual is a Raise_Expression, whose |
| -- type is imposed from context. |
| |
| elsif (Present (A) and then Etype (A) = Any_Type) |
| or else Etype (F) = Any_Type |
| then |
| if Nkind (A) /= N_Raise_Expression then |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| end if; |
| |
| -- Case where actual is present |
| |
| -- If the actual is an entity, generate a reference to it now. We |
| -- do this before the actual is resolved, because a formal of some |
| -- protected subprogram, or a task discriminant, will be rewritten |
| -- during expansion, and the source entity reference may be lost. |
| |
| if Present (A) |
| and then Is_Entity_Name (A) |
| and then Comes_From_Source (N) |
| then |
| Orig_A := Entity (A); |
| |
| if Present (Orig_A) then |
| if Is_Formal (Orig_A) |
| and then Ekind (F) /= E_In_Parameter |
| then |
| Generate_Reference (Orig_A, A, 'm'); |
| |
| elsif not Is_Overloaded (A) then |
| if Ekind (F) /= E_Out_Parameter then |
| Generate_Reference (Orig_A, A); |
| |
| -- RM 6.4.1(12): For an out parameter that is passed by |
| -- copy, the formal parameter object is created, and: |
| |
| -- * For an access type, the formal parameter is initialized |
| -- from the value of the actual, without checking that the |
| -- value satisfies any constraint, any predicate, or any |
| -- exclusion of the null value. |
| |
| -- * For a scalar type that has the Default_Value aspect |
| -- specified, the formal parameter is initialized from the |
| -- value of the actual, without checking that the value |
| -- satisfies any constraint or any predicate. |
| -- I do not understand why this case is included??? this is |
| -- not a case where an OUT parameter is treated as IN OUT. |
| |
| -- * For a composite type with discriminants or that has |
| -- implicit initial values for any subcomponents, the |
| -- behavior is as for an in out parameter passed by copy. |
| |
| -- Hence for these cases we generate the read reference now |
| -- (the write reference will be generated later by |
| -- Note_Possible_Modification). |
| |
| elsif Is_By_Copy_Type (Etype (F)) |
| and then |
| (Is_Access_Type (Etype (F)) |
| or else |
| (Is_Scalar_Type (Etype (F)) |
| and then |
| Present (Default_Aspect_Value (Etype (F)))) |
| or else |
| (Is_Composite_Type (Etype (F)) |
| and then (Has_Discriminants (Etype (F)) |
| or else Is_Partially_Initialized_Type |
| (Etype (F))))) |
| then |
| Generate_Reference (Orig_A, A); |
| end if; |
| end if; |
| end if; |
| end if; |
| |
| if Present (A) |
| and then (Nkind (Parent (A)) /= N_Parameter_Association |
| or else Chars (Selector_Name (Parent (A))) = Chars (F)) |
| then |
| -- If style checking mode on, check match of formal name |
| |
| if Style_Check then |
| if Nkind (Parent (A)) = N_Parameter_Association then |
| Check_Identifier (Selector_Name (Parent (A)), F); |
| end if; |
| end if; |
| |
| -- If the formal is Out or In_Out, do not resolve and expand the |
| -- conversion, because it is subsequently expanded into explicit |
| -- temporaries and assignments. However, the object of the |
| -- conversion can be resolved. An exception is the case of tagged |
| -- type conversion with a class-wide actual. In that case we want |
| -- the tag check to occur and no temporary will be needed (no |
| -- representation change can occur) and the parameter is passed by |
| -- reference, so we go ahead and resolve the type conversion. |
| -- Another exception is the case of reference to component or |
| -- subcomponent of a bit-packed array, in which case we want to |
| -- defer expansion to the point the in and out assignments are |
| -- performed. |
| |
| if Ekind (F) /= E_In_Parameter |
| and then Nkind (A) = N_Type_Conversion |
| and then not Is_Class_Wide_Type (Etype (Expression (A))) |
| then |
| if Ekind (F) = E_In_Out_Parameter |
| and then Is_Array_Type (Etype (F)) |
| then |
| -- In a view conversion, the conversion must be legal in |
| -- both directions, and thus both component types must be |
| -- aliased, or neither (4.6 (8)). |
| |
| -- The extra rule in 4.6 (24.9.2) seems unduly restrictive: |
| -- the privacy requirement should not apply to generic |
| -- types, and should be checked in an instance. ARG query |
| -- is in order ??? |
| |
| if Has_Aliased_Components (Etype (Expression (A))) /= |
| Has_Aliased_Components (Etype (F)) |
| then |
| Error_Msg_N |
| ("both component types in a view conversion must be" |
| & " aliased, or neither", A); |
| |
| -- Comment here??? what set of cases??? |
| |
| elsif |
| not Same_Ancestor (Etype (F), Etype (Expression (A))) |
| then |
| -- Check view conv between unrelated by ref array types |
| |
| if Is_By_Reference_Type (Etype (F)) |
| or else Is_By_Reference_Type (Etype (Expression (A))) |
| then |
| Error_Msg_N |
| ("view conversion between unrelated by reference " |
| & "array types not allowed (\'A'I-00246)", A); |
| |
| -- In Ada 2005 mode, check view conversion component |
| -- type cannot be private, tagged, or volatile. Note |
| -- that we only apply this to source conversions. The |
| -- generated code can contain conversions which are |
| -- not subject to this test, and we cannot extract the |
| -- component type in such cases since it is not present. |
| |
| elsif Comes_From_Source (A) |
| and then Ada_Version >= Ada_2005 |
| then |
| declare |
| Comp_Type : constant Entity_Id := |
| Component_Type |
| (Etype (Expression (A))); |
| begin |
| if (Is_Private_Type (Comp_Type) |
| and then not Is_Generic_Type (Comp_Type)) |
| or else Is_Tagged_Type (Comp_Type) |
| or else Is_Volatile (Comp_Type) |
| then |
| Error_Msg_N |
| ("component type of a view conversion cannot" |
| & " be private, tagged, or volatile" |
| & " (RM 4.6 (24))", |
| Expression (A)); |
| end if; |
| end; |
| end if; |
| end if; |
| end if; |
| |
| -- Resolve expression if conversion is all OK |
| |
| if (Conversion_OK (A) |
| or else Valid_Conversion (A, Etype (A), Expression (A))) |
| and then not Is_Ref_To_Bit_Packed_Array (Expression (A)) |
| then |
| Resolve (Expression (A)); |
| end if; |
| |
| -- If the actual is a function call that returns a limited |
| -- unconstrained object that needs finalization, create a |
| -- transient scope for it, so that it can receive the proper |
| -- finalization list. |
| |
| elsif Nkind (A) = N_Function_Call |
| and then Is_Limited_Record (Etype (F)) |
| and then not Is_Constrained (Etype (F)) |
| and then Expander_Active |
| and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F))) |
| then |
| Establish_Transient_Scope (A, Sec_Stack => False); |
| Resolve (A, Etype (F)); |
| |
| -- A small optimization: if one of the actuals is a concatenation |
| -- create a block around a procedure call to recover stack space. |
| -- This alleviates stack usage when several procedure calls in |
| -- the same statement list use concatenation. We do not perform |
| -- this wrapping for code statements, where the argument is a |
| -- static string, and we want to preserve warnings involving |
| -- sequences of such statements. |
| |
| elsif Nkind (A) = N_Op_Concat |
| and then Nkind (N) = N_Procedure_Call_Statement |
| and then Expander_Active |
| and then |
| not (Is_Intrinsic_Subprogram (Nam) |
| and then Chars (Nam) = Name_Asm) |
| and then not Static_Concatenation (A) |
| then |
| Establish_Transient_Scope (A, Sec_Stack => False); |
| Resolve (A, Etype (F)); |
| |
| else |
| if Nkind (A) = N_Type_Conversion |
| and then Is_Array_Type (Etype (F)) |
| and then not Same_Ancestor (Etype (F), Etype (Expression (A))) |
| and then |
| (Is_Limited_Type (Etype (F)) |
| or else Is_Limited_Type (Etype (Expression (A)))) |
| then |
| Error_Msg_N |
| ("conversion between unrelated limited array types " |
| & "not allowed ('A'I-00246)", A); |
| |
| if Is_Limited_Type (Etype (F)) then |
| Explain_Limited_Type (Etype (F), A); |
| end if; |
| |
| if Is_Limited_Type (Etype (Expression (A))) then |
| Explain_Limited_Type (Etype (Expression (A)), A); |
| end if; |
| end if; |
| |
| -- (Ada 2005: AI-251): If the actual is an allocator whose |
| -- directly designated type is a class-wide interface, we build |
| -- an anonymous access type to use it as the type of the |
| -- allocator. Later, when the subprogram call is expanded, if |
| -- the interface has a secondary dispatch table the expander |
| -- will add a type conversion to force the correct displacement |
| -- of the pointer. |
| |
| if Nkind (A) = N_Allocator then |
| declare |
| DDT : constant Entity_Id := |
| Directly_Designated_Type (Base_Type (Etype (F))); |
| |
| New_Itype : Entity_Id; |
| |
| begin |
| if Is_Class_Wide_Type (DDT) |
| and then Is_Interface (DDT) |
| then |
| New_Itype := Create_Itype (E_Anonymous_Access_Type, A); |
| Set_Etype (New_Itype, Etype (A)); |
| Set_Directly_Designated_Type |
| (New_Itype, Directly_Designated_Type (Etype (A))); |
| Set_Etype (A, New_Itype); |
| end if; |
| |
| -- Ada 2005, AI-162:If the actual is an allocator, the |
| -- innermost enclosing statement is the master of the |
| -- created object. This needs to be done with expansion |
| -- enabled only, otherwise the transient scope will not |
| -- be removed in the expansion of the wrapped construct. |
| |
| if (Is_Controlled (DDT) or else Has_Task (DDT)) |
| and then Expander_Active |
| then |
| Establish_Transient_Scope (A, Sec_Stack => False); |
| end if; |
| end; |
| |
| if Ekind (Etype (F)) = E_Anonymous_Access_Type then |
| Check_Restriction (No_Access_Parameter_Allocators, A); |
| end if; |
| end if; |
| |
| -- (Ada 2005): The call may be to a primitive operation of a |
| -- tagged synchronized type, declared outside of the type. In |
| -- this case the controlling actual must be converted to its |
| -- corresponding record type, which is the formal type. The |
| -- actual may be a subtype, either because of a constraint or |
| -- because it is a generic actual, so use base type to locate |
| -- concurrent type. |
| |
| F_Typ := Base_Type (Etype (F)); |
| |
| if Is_Tagged_Type (F_Typ) |
| and then (Is_Concurrent_Type (F_Typ) |
| or else Is_Concurrent_Record_Type (F_Typ)) |
| then |
| -- If the actual is overloaded, look for an interpretation |
| -- that has a synchronized type. |
| |
| if not Is_Overloaded (A) then |
| A_Typ := Base_Type (Etype (A)); |
| |
| else |
| declare |
| Index : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (A, Index, It); |
| while Present (It.Typ) loop |
| if Is_Concurrent_Type (It.Typ) |
| or else Is_Concurrent_Record_Type (It.Typ) |
| then |
| A_Typ := Base_Type (It.Typ); |
| exit; |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| end; |
| end if; |
| |
| declare |
| Full_A_Typ : Entity_Id; |
| |
| begin |
| if Present (Full_View (A_Typ)) then |
| Full_A_Typ := Base_Type (Full_View (A_Typ)); |
| else |
| Full_A_Typ := A_Typ; |
| end if; |
| |
| -- Tagged synchronized type (case 1): the actual is a |
| -- concurrent type. |
| |
| if Is_Concurrent_Type (A_Typ) |
| and then Corresponding_Record_Type (A_Typ) = F_Typ |
| then |
| Rewrite (A, |
| Unchecked_Convert_To |
| (Corresponding_Record_Type (A_Typ), A)); |
| Resolve (A, Etype (F)); |
| |
| -- Tagged synchronized type (case 2): the formal is a |
| -- concurrent type. |
| |
| elsif Ekind (Full_A_Typ) = E_Record_Type |
| and then Present |
| (Corresponding_Concurrent_Type (Full_A_Typ)) |
| and then Is_Concurrent_Type (F_Typ) |
| and then Present (Corresponding_Record_Type (F_Typ)) |
| and then Full_A_Typ = Corresponding_Record_Type (F_Typ) |
| then |
| Resolve (A, Corresponding_Record_Type (F_Typ)); |
| |
| -- Common case |
| |
| else |
| Resolve (A, Etype (F)); |
| end if; |
| end; |
| |
| -- Not a synchronized operation |
| |
| else |
| Resolve (A, Etype (F)); |
| end if; |
| end if; |
| |
| A_Typ := Etype (A); |
| F_Typ := Etype (F); |
| |
| if Comes_From_Source (Original_Node (N)) |
| and then Nkind_In (Original_Node (N), N_Function_Call, |
| N_Procedure_Call_Statement) |
| then |
| -- In formal mode, check that actual parameters matching |
| -- formals of tagged types are objects (or ancestor type |
| -- conversions of objects), not general expressions. |
| |
| if Is_Actual_Tagged_Parameter (A) then |
| if Is_SPARK_Object_Reference (A) then |
| null; |
| |
| elsif Nkind (A) = N_Type_Conversion then |
| declare |
| Operand : constant Node_Id := Expression (A); |
| Operand_Typ : constant Entity_Id := Etype (Operand); |
| Target_Typ : constant Entity_Id := A_Typ; |
| |
| begin |
| if not Is_SPARK_Object_Reference (Operand) then |
| Check_SPARK_Restriction |
| ("object required", Operand); |
| |
| -- In formal mode, the only view conversions are those |
| -- involving ancestor conversion of an extended type. |
| |
| elsif not |
| (Is_Tagged_Type (Target_Typ) |
| and then not Is_Class_Wide_Type (Target_Typ) |
| and then Is_Tagged_Type (Operand_Typ) |
| and then not Is_Class_Wide_Type (Operand_Typ) |
| and then Is_Ancestor (Target_Typ, Operand_Typ)) |
| then |
| if Ekind_In |
| (F, E_Out_Parameter, E_In_Out_Parameter) |
| then |
| Check_SPARK_Restriction |
| ("ancestor conversion is the only permitted " |
| & "view conversion", A); |
| else |
| Check_SPARK_Restriction |
| ("ancestor conversion required", A); |
| end if; |
| |
| else |
| null; |
| end if; |
| end; |
| |
| else |
| Check_SPARK_Restriction ("object required", A); |
| end if; |
| |
| -- In formal mode, the only view conversions are those |
| -- involving ancestor conversion of an extended type. |
| |
| elsif Nkind (A) = N_Type_Conversion |
| and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) |
| then |
| Check_SPARK_Restriction |
| ("ancestor conversion is the only permitted view " |
| & "conversion", A); |
| end if; |
| end if; |
| |
| -- has warnings suppressed, then we reset Never_Set_In_Source for |
| -- the calling entity. The reason for this is to catch cases like |
| -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram |
| -- uses trickery to modify an IN parameter. |
| |
| if Ekind (F) = E_In_Parameter |
| and then Is_Entity_Name (A) |
| and then Present (Entity (A)) |
| and then Ekind (Entity (A)) = E_Variable |
| and then Has_Warnings_Off (F_Typ) |
| then |
| Set_Never_Set_In_Source (Entity (A), False); |
| end if; |
| |
| -- Perform error checks for IN and IN OUT parameters |
| |
| if Ekind (F) /= E_Out_Parameter then |
| |
| -- Check unset reference. For scalar parameters, it is clearly |
| -- wrong to pass an uninitialized value as either an IN or |
| -- IN-OUT parameter. For composites, it is also clearly an |
| -- error to pass a completely uninitialized value as an IN |
| -- parameter, but the case of IN OUT is trickier. We prefer |
| -- not to give a warning here. For example, suppose there is |
| -- a routine that sets some component of a record to False. |
| -- It is perfectly reasonable to make this IN-OUT and allow |
| -- either initialized or uninitialized records to be passed |
| -- in this case. |
| |
| -- For partially initialized composite values, we also avoid |
| -- warnings, since it is quite likely that we are passing a |
| -- partially initialized value and only the initialized fields |
| -- will in fact be read in the subprogram. |
| |
| if Is_Scalar_Type (A_Typ) |
| or else (Ekind (F) = E_In_Parameter |
| and then not Is_Partially_Initialized_Type (A_Typ)) |
| then |
| Check_Unset_Reference (A); |
| end if; |
| |
| -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT |
| -- actual to a nested call, since this is case of reading an |
| -- out parameter, which is not allowed. |
| |
| if Ada_Version = Ada_83 |
| and then Is_Entity_Name (A) |
| and then Ekind (Entity (A)) = E_Out_Parameter |
| then |
| Error_Msg_N ("(Ada 83) illegal reading of out parameter", A); |
| end if; |
| end if; |
| |
| -- Case of OUT or IN OUT parameter |
| |
| if Ekind (F) /= E_In_Parameter then |
| |
| -- For an Out parameter, check for useless assignment. Note |
| -- that we can't set Last_Assignment this early, because we may |
| -- kill current values in Resolve_Call, and that call would |
| -- clobber the Last_Assignment field. |
| |
| -- Note: call Warn_On_Useless_Assignment before doing the check |
| -- below for Is_OK_Variable_For_Out_Formal so that the setting |
| -- of Referenced_As_LHS/Referenced_As_Out_Formal properly |
| -- reflects the last assignment, not this one. |
| |
| if Ekind (F) = E_Out_Parameter then |
| if Warn_On_Modified_As_Out_Parameter (F) |
| and then Is_Entity_Name (A) |
| and then Present (Entity (A)) |
| and then Comes_From_Source (N) |
| then |
| Warn_On_Useless_Assignment (Entity (A), A); |
| end if; |
| end if; |
| |
| -- Validate the form of the actual. Note that the call to |
| -- Is_OK_Variable_For_Out_Formal generates the required |
| -- reference in this case. |
| |
| -- A call to an initialization procedure for an aggregate |
| -- component may initialize a nested component of a constant |
| -- designated object. In this context the object is variable. |
| |
| if not Is_OK_Variable_For_Out_Formal (A) |
| and then not Is_Init_Proc (Nam) |
| then |
| Error_Msg_NE ("actual for& must be a variable", A, F); |
| |
| if Is_Subprogram (Current_Scope) |
| and then |
| (Is_Invariant_Procedure (Current_Scope) |
| or else Is_Predicate_Function (Current_Scope)) |
| then |
| Error_Msg_N |
| ("function used in predicate cannot " |
| & "modify its argument", F); |
| end if; |
| end if; |
| |
| -- What's the following about??? |
| |
| if Is_Entity_Name (A) then |
| Kill_Checks (Entity (A)); |
| else |
| Kill_All_Checks; |
| end if; |
| end if; |
| |
| if Etype (A) = Any_Type then |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| -- Apply appropriate range checks for in, out, and in-out |
| -- parameters. Out and in-out parameters also need a separate |
| -- check, if there is a type conversion, to make sure the return |
| -- value meets the constraints of the variable before the |
| -- conversion. |
| |
| -- Gigi looks at the check flag and uses the appropriate types. |
| -- For now since one flag is used there is an optimization which |
| -- might not be done in the In Out case since Gigi does not do |
| -- any analysis. More thought required about this ??? |
| |
| if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then |
| |
| -- Apply predicate checks, unless this is a call to the |
| -- predicate check function itself, which would cause an |
| -- infinite recursion, or it is a call to an initialization |
| -- procedure whose operand is of course an unfinished object. |
| |
| if not (Ekind (Nam) = E_Function |
| and then (Is_Predicate_Function (Nam) |
| or else |
| Is_Predicate_Function_M (Nam))) |
| and then not Is_Init_Proc (Nam) |
| then |
| Apply_Predicate_Check (A, F_Typ); |
| end if; |
| |
| -- Apply required constraint checks |
| |
| if Is_Scalar_Type (Etype (A)) then |
| Apply_Scalar_Range_Check (A, F_Typ); |
| |
| elsif Is_Array_Type (Etype (A)) then |
| Apply_Length_Check (A, F_Typ); |
| |
| elsif Is_Record_Type (F_Typ) |
| and then Has_Discriminants (F_Typ) |
| and then Is_Constrained (F_Typ) |
| and then (not Is_Derived_Type (F_Typ) |
| or else Comes_From_Source (Nam)) |
| then |
| Apply_Discriminant_Check (A, F_Typ); |
| |
| -- For view conversions of a discriminated object, apply |
| -- check to object itself, the conversion alreay has the |
| -- proper type. |
| |
| if Nkind (A) = N_Type_Conversion |
| and then Is_Constrained (Etype (Expression (A))) |
| then |
| Apply_Discriminant_Check (Expression (A), F_Typ); |
| end if; |
| |
| elsif Is_Access_Type (F_Typ) |
| and then Is_Array_Type (Designated_Type (F_Typ)) |
| and then Is_Constrained (Designated_Type (F_Typ)) |
| then |
| Apply_Length_Check (A, F_Typ); |
| |
| elsif Is_Access_Type (F_Typ) |
| and then Has_Discriminants (Designated_Type (F_Typ)) |
| and then Is_Constrained (Designated_Type (F_Typ)) |
| then |
| Apply_Discriminant_Check (A, F_Typ); |
| |
| else |
| Apply_Range_Check (A, F_Typ); |
| end if; |
| |
| -- Ada 2005 (AI-231): Note that the controlling parameter case |
| -- already existed in Ada 95, which is partially checked |
| -- elsewhere (see Checks), and we don't want the warning |
| -- message to differ. |
| |
| if Is_Access_Type (F_Typ) |
| and then Can_Never_Be_Null (F_Typ) |
| and then Known_Null (A) |
| then |
| if Is_Controlling_Formal (F) then |
| Apply_Compile_Time_Constraint_Error |
| (N => A, |
| Msg => "null value not allowed here??", |
| Reason => CE_Access_Check_Failed); |
| |
| elsif Ada_Version >= Ada_2005 then |
| Apply_Compile_Time_Constraint_Error |
| (N => A, |
| Msg => "(Ada 2005) null not allowed in " |
| & "null-excluding formal??", |
| Reason => CE_Null_Not_Allowed); |
| end if; |
| end if; |
| end if; |
| |
| if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then |
| if Nkind (A) = N_Type_Conversion then |
| if Is_Scalar_Type (A_Typ) then |
| Apply_Scalar_Range_Check |
| (Expression (A), Etype (Expression (A)), A_Typ); |
| else |
| Apply_Range_Check |
| (Expression (A), Etype (Expression (A)), A_Typ); |
| end if; |
| |
| else |
| if Is_Scalar_Type (F_Typ) then |
| Apply_Scalar_Range_Check (A, A_Typ, F_Typ); |
| elsif Is_Array_Type (F_Typ) |
| and then Ekind (F) = E_Out_Parameter |
| then |
| Apply_Length_Check (A, F_Typ); |
| else |
| Apply_Range_Check (A, A_Typ, F_Typ); |
| end if; |
| end if; |
| end if; |
| |
| -- An actual associated with an access parameter is implicitly |
| -- converted to the anonymous access type of the formal and must |
| -- satisfy the legality checks for access conversions. |
| |
| if Ekind (F_Typ) = E_Anonymous_Access_Type then |
| if not Valid_Conversion (A, F_Typ, A) then |
| Error_Msg_N |
| ("invalid implicit conversion for access parameter", A); |
| end if; |
| |
| -- If the actual is an access selected component of a variable, |
| -- the call may modify its designated object. It is reasonable |
| -- to treat this as a potential modification of the enclosing |
| -- record, to prevent spurious warnings that it should be |
| -- declared as a constant, because intuitively programmers |
| -- regard the designated subcomponent as part of the record. |
| |
| if Nkind (A) = N_Selected_Component |
| and then Is_Entity_Name (Prefix (A)) |
| and then not Is_Constant_Object (Entity (Prefix (A))) |
| then |
| Note_Possible_Modification (A, Sure => False); |
| end if; |
| end if; |
| |
| -- Check bad case of atomic/volatile argument (RM C.6(12)) |
| |
| if Is_By_Reference_Type (Etype (F)) |
| and then Comes_From_Source (N) |
| then |
| if Is_Atomic_Object (A) |
| and then not Is_Atomic (Etype (F)) |
| then |
| Error_Msg_NE |
| ("cannot pass atomic argument to non-atomic formal&", |
| A, F); |
| |
| elsif Is_Volatile_Object (A) |
| and then not Is_Volatile (Etype (F)) |
| then |
| Error_Msg_NE |
| ("cannot pass volatile argument to non-volatile formal&", |
| A, F); |
| end if; |
| end if; |
| |
| -- Check that subprograms don't have improper controlling |
| -- arguments (RM 3.9.2 (9)). |
| |
| -- A primitive operation may have an access parameter of an |
| -- incomplete tagged type, but a dispatching call is illegal |
| -- if the type is still incomplete. |
| |
| if Is_Controlling_Formal (F) then |
| Set_Is_Controlling_Actual (A); |
| |
| if Ekind (Etype (F)) = E_Anonymous_Access_Type then |
| declare |
| Desig : constant Entity_Id := Designated_Type (Etype (F)); |
| begin |
| if Ekind (Desig) = E_Incomplete_Type |
| and then No (Full_View (Desig)) |
| and then No (Non_Limited_View (Desig)) |
| then |
| Error_Msg_NE |
| ("premature use of incomplete type& " |
| & "in dispatching call", A, Desig); |
| end if; |
| end; |
| end if; |
| |
| elsif Nkind (A) = N_Explicit_Dereference then |
| Validate_Remote_Access_To_Class_Wide_Type (A); |
| end if; |
| |
| if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A)) |
| and then not Is_Class_Wide_Type (F_Typ) |
| and then not Is_Controlling_Formal (F) |
| then |
| Error_Msg_N ("class-wide argument not allowed here!", A); |
| |
| if Is_Subprogram (Nam) |
| and then Comes_From_Source (Nam) |
| then |
| Error_Msg_Node_2 := F_Typ; |
| Error_Msg_NE |
| ("& is not a dispatching operation of &!", A, Nam); |
| end if; |
| |
| -- Apply the checks described in 3.10.2(27): if the context is a |
| -- specific access-to-object, the actual cannot be class-wide. |
| -- Use base type to exclude access_to_subprogram cases. |
| |
| elsif Is_Access_Type (A_Typ) |
| and then Is_Access_Type (F_Typ) |
| and then not Is_Access_Subprogram_Type (Base_Type (F_Typ)) |
| and then (Is_Class_Wide_Type (Designated_Type (A_Typ)) |
| or else (Nkind (A) = N_Attribute_Reference |
| and then |
| Is_Class_Wide_Type (Etype (Prefix (A))))) |
| and then not Is_Class_Wide_Type (Designated_Type (F_Typ)) |
| and then not Is_Controlling_Formal (F) |
| |
| -- Disable these checks for call to imported C++ subprograms |
| |
| and then not |
| (Is_Entity_Name (Name (N)) |
| and then Is_Imported (Entity (Name (N))) |
| and then Convention (Entity (Name (N))) = Convention_CPP) |
| then |
| Error_Msg_N |
| ("access to class-wide argument not allowed here!", A); |
| |
| if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then |
| Error_Msg_Node_2 := Designated_Type (F_Typ); |
| Error_Msg_NE |
| ("& is not a dispatching operation of &!", A, Nam); |
| end if; |
| end if; |
| |
| Eval_Actual (A); |
| |
| -- If it is a named association, treat the selector_name as a |
| -- proper identifier, and mark the corresponding entity. |
| |
| if Nkind (Parent (A)) = N_Parameter_Association |
| |
| -- Ignore reference in SPARK mode, as it refers to an entity not |
| -- in scope at the point of reference, so the reference should |
| -- be ignored for computing effects of subprograms. |
| |
| and then not GNATprove_Mode |
| then |
| Set_Entity (Selector_Name (Parent (A)), F); |
| Generate_Reference (F, Selector_Name (Parent (A))); |
| Set_Etype (Selector_Name (Parent (A)), F_Typ); |
| Generate_Reference (F_Typ, N, ' '); |
| end if; |
| |
| Prev := A; |
| |
| if Ekind (F) /= E_Out_Parameter then |
| Check_Unset_Reference (A); |
| end if; |
| |
| -- The following checks are only relevant when SPARK_Mode is on as |
| -- they are not standard Ada legality rule. |
| |
| if SPARK_Mode = On |
| and then Is_SPARK_Volatile_Object (A) |
| then |
| -- A volatile object may act as an actual parameter when the |
| -- corresponding formal is of a non-scalar volatile type. |
| |
| if Is_Volatile (Etype (F)) |
| and then not Is_Scalar_Type (Etype (F)) |
| then |
| null; |
| |
| -- A volatile object may act as an actual parameter in a call |
| -- to an instance of Unchecked_Conversion. |
| |
| elsif Is_Unchecked_Conversion_Instance (Nam) then |
| null; |
| |
| else |
| Error_Msg_N |
| ("volatile object cannot act as actual in a call (SPARK " |
| & "RM 7.1.3(12))", A); |
| end if; |
| |
| -- Detect an external variable with an enabled property that |
| -- does not match the mode of the corresponding formal in a |
| -- procedure call. |
| |
| -- why only procedure calls ??? |
| |
| if Ekind (Nam) = E_Procedure |
| and then Is_Entity_Name (A) |
| and then Present (Entity (A)) |
| and then Ekind (Entity (A)) = E_Variable |
| then |
| A_Id := Entity (A); |
| |
| if Ekind (F) = E_In_Parameter then |
| if Async_Readers_Enabled (A_Id) then |
| Property_Error (A, A_Id, Name_Async_Readers); |
| elsif Effective_Reads_Enabled (A_Id) then |
| Property_Error (A, A_Id, Name_Effective_Reads); |
| elsif Effective_Writes_Enabled (A_Id) then |
| Property_Error (A, A_Id, Name_Effective_Writes); |
| end if; |
| |
| elsif Ekind (F) = E_Out_Parameter |
| and then Async_Writers_Enabled (A_Id) |
| then |
| Error_Msg_Name_1 := Name_Async_Writers; |
| Error_Msg_NE |
| ("external variable & with enabled property % cannot " |
| & "appear as actual in procedure call " |
| & "(SPARK RM 7.1.3(11))", A, A_Id); |
| Error_Msg_N |
| ("\\corresponding formal parameter has mode Out", A); |
| end if; |
| end if; |
| end if; |
| |
| Next_Actual (A); |
| |
| -- Case where actual is not present |
| |
| else |
| Insert_Default; |
| end if; |
| |
| Next_Formal (F); |
| end loop; |
| end Resolve_Actuals; |
| |
| ----------------------- |
| -- Resolve_Allocator -- |
| ----------------------- |
| |
| procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is |
| Desig_T : constant Entity_Id := Designated_Type (Typ); |
| E : constant Node_Id := Expression (N); |
| Subtyp : Entity_Id; |
| Discrim : Entity_Id; |
| Constr : Node_Id; |
| Aggr : Node_Id; |
| Assoc : Node_Id := Empty; |
| Disc_Exp : Node_Id; |
| |
| procedure Check_Allocator_Discrim_Accessibility |
| (Disc_Exp : Node_Id; |
| Alloc_Typ : Entity_Id); |
| -- Check that accessibility level associated with an access discriminant |
| -- initialized in an allocator by the expression Disc_Exp is not deeper |
| -- than the level of the allocator type Alloc_Typ. An error message is |
| -- issued if this condition is violated. Specialized checks are done for |
| -- the cases of a constraint expression which is an access attribute or |
| -- an access discriminant. |
| |
| function In_Dispatching_Context return Boolean; |
| -- If the allocator is an actual in a call, it is allowed to be class- |
| -- wide when the context is not because it is a controlling actual. |
| |
| ------------------------------------------- |
| -- Check_Allocator_Discrim_Accessibility -- |
| ------------------------------------------- |
| |
| procedure Check_Allocator_Discrim_Accessibility |
| (Disc_Exp : Node_Id; |
| Alloc_Typ : Entity_Id) |
| is |
| begin |
| if Type_Access_Level (Etype (Disc_Exp)) > |
| Deepest_Type_Access_Level (Alloc_Typ) |
| then |
| Error_Msg_N |
| ("operand type has deeper level than allocator type", Disc_Exp); |
| |
| -- When the expression is an Access attribute the level of the prefix |
| -- object must not be deeper than that of the allocator's type. |
| |
| elsif Nkind (Disc_Exp) = N_Attribute_Reference |
| and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) = |
| Attribute_Access |
| and then Object_Access_Level (Prefix (Disc_Exp)) > |
| Deepest_Type_Access_Level (Alloc_Typ) |
| then |
| Error_Msg_N |
| ("prefix of attribute has deeper level than allocator type", |
| Disc_Exp); |
| |
| -- When the expression is an access discriminant the check is against |
| -- the level of the prefix object. |
| |
| elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type |
| and then Nkind (Disc_Exp) = N_Selected_Component |
| and then Object_Access_Level (Prefix (Disc_Exp)) > |
| Deepest_Type_Access_Level (Alloc_Typ) |
| then |
| Error_Msg_N |
| ("access discriminant has deeper level than allocator type", |
| Disc_Exp); |
| |
| -- All other cases are legal |
| |
| else |
| null; |
| end if; |
| end Check_Allocator_Discrim_Accessibility; |
| |
| ---------------------------- |
| -- In_Dispatching_Context -- |
| ---------------------------- |
| |
| function In_Dispatching_Context return Boolean is |
| Par : constant Node_Id := Parent (N); |
| |
| begin |
| return Nkind (Par) in N_Subprogram_Call |
| and then Is_Entity_Name (Name (Par)) |
| and then Is_Dispatching_Operation (Entity (Name (Par))); |
| end In_Dispatching_Context; |
| |
| -- Start of processing for Resolve_Allocator |
| |
| begin |
| -- Replace general access with specific type |
| |
| if Ekind (Etype (N)) = E_Allocator_Type then |
| Set_Etype (N, Base_Type (Typ)); |
| end if; |
| |
| if Is_Abstract_Type (Typ) then |
| Error_Msg_N ("type of allocator cannot be abstract", N); |
| end if; |
| |
| -- For qualified expression, resolve the expression using the given |
| -- subtype (nothing to do for type mark, subtype indication) |
| |
| if Nkind (E) = N_Qualified_Expression then |
| if Is_Class_Wide_Type (Etype (E)) |
| and then not Is_Class_Wide_Type (Desig_T) |
| and then not In_Dispatching_Context |
| then |
| Error_Msg_N |
| ("class-wide allocator not allowed for this access type", N); |
| end if; |
| |
| Resolve (Expression (E), Etype (E)); |
| Check_Unset_Reference (Expression (E)); |
| |
| -- A qualified expression requires an exact match of the type. |
| -- Class-wide matching is not allowed. |
| |
| if (Is_Class_Wide_Type (Etype (Expression (E))) |
| or else Is_Class_Wide_Type (Etype (E))) |
| and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E)) |
| then |
| Wrong_Type (Expression (E), Etype (E)); |
| end if; |
| |
| -- Calls to build-in-place functions are not currently supported in |
| -- allocators for access types associated with a simple storage pool. |
| -- Supporting such allocators may require passing additional implicit |
| -- parameters to build-in-place functions (or a significant revision |
| -- of the current b-i-p implementation to unify the handling for |
| -- multiple kinds of storage pools). ??? |
| |
| if Is_Limited_View (Desig_T) |
| and then Nkind (Expression (E)) = N_Function_Call |
| then |
| declare |
| Pool : constant Entity_Id := |
| Associated_Storage_Pool (Root_Type (Typ)); |
| begin |
| if Present (Pool) |
| and then |
| Present (Get_Rep_Pragma |
| (Etype (Pool), Name_Simple_Storage_Pool_Type)) |
| then |
| Error_Msg_N |
| ("limited function calls not yet supported in simple " |
| & "storage pool allocators", Expression (E)); |
| end if; |
| end; |
| end if; |
| |
| -- A special accessibility check is needed for allocators that |
| -- constrain access discriminants. The level of the type of the |
| -- expression used to constrain an access discriminant cannot be |
| -- deeper than the type of the allocator (in contrast to access |
| -- parameters, where the level of the actual can be arbitrary). |
| |
| -- We can't use Valid_Conversion to perform this check because in |
| -- general the type of the allocator is unrelated to the type of |
| -- the access discriminant. |
| |
| if Ekind (Typ) /= E_Anonymous_Access_Type |
| or else Is_Local_Anonymous_Access (Typ) |
| then |
| Subtyp := Entity (Subtype_Mark (E)); |
| |
| Aggr := Original_Node (Expression (E)); |
| |
| if Has_Discriminants (Subtyp) |
| and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate) |
| then |
| Discrim := First_Discriminant (Base_Type (Subtyp)); |
| |
| -- Get the first component expression of the aggregate |
| |
| if Present (Expressions (Aggr)) then |
| Disc_Exp := First (Expressions (Aggr)); |
| |
| elsif Present (Component_Associations (Aggr)) then |
| Assoc := First (Component_Associations (Aggr)); |
| |
| if Present (Assoc) then |
| Disc_Exp := Expression (Assoc); |
| else |
| Disc_Exp := Empty; |
| end if; |
| |
| else |
| Disc_Exp := Empty; |
| end if; |
| |
| while Present (Discrim) and then Present (Disc_Exp) loop |
| if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then |
| Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ); |
| end if; |
| |
| Next_Discriminant (Discrim); |
| |
| if Present (Discrim) then |
| if Present (Assoc) then |
| Next (Assoc); |
| Disc_Exp := Expression (Assoc); |
| |
| elsif Present (Next (Disc_Exp)) then |
| Next (Disc_Exp); |
| |
| else |
| Assoc := First (Component_Associations (Aggr)); |
| |
| if Present (Assoc) then |
| Disc_Exp := Expression (Assoc); |
| else |
| Disc_Exp := Empty; |
| end if; |
| end if; |
| end if; |
| end loop; |
| end if; |
| end if; |
| |
| -- For a subtype mark or subtype indication, freeze the subtype |
| |
| else |
| Freeze_Expression (E); |
| |
| if Is_Access_Constant (Typ) and then not No_Initialization (N) then |
| Error_Msg_N |
| ("initialization required for access-to-constant allocator", N); |
| end if; |
| |
| -- A special accessibility check is needed for allocators that |
| -- constrain access discriminants. The level of the type of the |
| -- expression used to constrain an access discriminant cannot be |
| -- deeper than the type of the allocator (in contrast to access |
| -- parameters, where the level of the actual can be arbitrary). |
| -- We can't use Valid_Conversion to perform this check because |
| -- in general the type of the allocator is unrelated to the type |
| -- of the access discriminant. |
| |
| if Nkind (Original_Node (E)) = N_Subtype_Indication |
| and then (Ekind (Typ) /= E_Anonymous_Access_Type |
| or else Is_Local_Anonymous_Access (Typ)) |
| then |
| Subtyp := Entity (Subtype_Mark (Original_Node (E))); |
| |
| if Has_Discriminants (Subtyp) then |
| Discrim := First_Discriminant (Base_Type (Subtyp)); |
| Constr := First (Constraints (Constraint (Original_Node (E)))); |
| while Present (Discrim) and then Present (Constr) loop |
| if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then |
| if Nkind (Constr) = N_Discriminant_Association then |
| Disc_Exp := Original_Node (Expression (Constr)); |
| else |
| Disc_Exp := Original_Node (Constr); |
| end if; |
| |
| Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ); |
| end if; |
| |
| Next_Discriminant (Discrim); |
| Next (Constr); |
| end loop; |
| end if; |
| end if; |
| end if; |
| |
| -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility |
| -- check that the level of the type of the created object is not deeper |
| -- than the level of the allocator's access type, since extensions can |
| -- now occur at deeper levels than their ancestor types. This is a |
| -- static accessibility level check; a run-time check is also needed in |
| -- the case of an initialized allocator with a class-wide argument (see |
| -- Expand_Allocator_Expression). |
| |
| if Ada_Version >= Ada_2005 |
| and then Is_Class_Wide_Type (Desig_T) |
| then |
| declare |
| Exp_Typ : Entity_Id; |
| |
| begin |
| if Nkind (E) = N_Qualified_Expression then |
| Exp_Typ := Etype (E); |
| elsif Nkind (E) = N_Subtype_Indication then |
| Exp_Typ := Entity (Subtype_Mark (Original_Node (E))); |
| else |
| Exp_Typ := Entity (E); |
| end if; |
| |
| if Type_Access_Level (Exp_Typ) > |
| Deepest_Type_Access_Level (Typ) |
| then |
| if In_Instance_Body then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_N |
| ("type in allocator has deeper level than " |
| & "designated class-wide type<<", E); |
| Error_Msg_N ("\Program_Error [<<", E); |
| Rewrite (N, |
| Make_Raise_Program_Error (Sloc (N), |
| Reason => PE_Accessibility_Check_Failed)); |
| Set_Etype (N, Typ); |
| |
| -- Do not apply Ada 2005 accessibility checks on a class-wide |
| -- allocator if the type given in the allocator is a formal |
| -- type. A run-time check will be performed in the instance. |
| |
| elsif not Is_Generic_Type (Exp_Typ) then |
| Error_Msg_N ("type in allocator has deeper level than " |
| & "designated class-wide type", E); |
| end if; |
| end if; |
| end; |
| end if; |
| |
| -- Check for allocation from an empty storage pool |
| |
| if No_Pool_Assigned (Typ) then |
| Error_Msg_N ("allocation from empty storage pool!", N); |
| |
| -- If the context is an unchecked conversion, as may happen within an |
| -- inlined subprogram, the allocator is being resolved with its own |
| -- anonymous type. In that case, if the target type has a specific |
| -- storage pool, it must be inherited explicitly by the allocator type. |
| |
| elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion |
| and then No (Associated_Storage_Pool (Typ)) |
| then |
| Set_Associated_Storage_Pool |
| (Typ, Associated_Storage_Pool (Etype (Parent (N)))); |
| end if; |
| |
| if Ekind (Etype (N)) = E_Anonymous_Access_Type then |
| Check_Restriction (No_Anonymous_Allocators, N); |
| end if; |
| |
| -- Check that an allocator with task parts isn't for a nested access |
| -- type when restriction No_Task_Hierarchy applies. |
| |
| if not Is_Library_Level_Entity (Base_Type (Typ)) |
| and then Has_Task (Base_Type (Desig_T)) |
| then |
| Check_Restriction (No_Task_Hierarchy, N); |
| end if; |
| |
| -- An erroneous allocator may be rewritten as a raise Program_Error |
| -- statement. |
| |
| if Nkind (N) = N_Allocator then |
| |
| -- An anonymous access discriminant is the definition of a |
| -- coextension. |
| |
| if Ekind (Typ) = E_Anonymous_Access_Type |
| and then Nkind (Associated_Node_For_Itype (Typ)) = |
| N_Discriminant_Specification |
| then |
| declare |
| Discr : constant Entity_Id := |
| Defining_Identifier (Associated_Node_For_Itype (Typ)); |
| |
| begin |
| Check_Restriction (No_Coextensions, N); |
| |
| -- Ada 2012 AI05-0052: If the designated type of the allocator |
| -- is limited, then the allocator shall not be used to define |
| -- the value of an access discriminant unless the discriminated |
| -- type is immutably limited. |
| |
| if Ada_Version >= Ada_2012 |
| and then Is_Limited_Type (Desig_T) |
| and then not Is_Limited_View (Scope (Discr)) |
| then |
| Error_Msg_N |
| ("only immutably limited types can have anonymous " |
| & "access discriminants designating a limited type", N); |
| end if; |
| end; |
| |
| -- Avoid marking an allocator as a dynamic coextension if it is |
| -- within a static construct. |
| |
| if not Is_Static_Coextension (N) then |
| Set_Is_Dynamic_Coextension (N); |
| end if; |
| |
| -- Cleanup for potential static coextensions |
| |
| else |
| Set_Is_Dynamic_Coextension (N, False); |
| Set_Is_Static_Coextension (N, False); |
| end if; |
| end if; |
| |
| -- Report a simple error: if the designated object is a local task, |
| -- its body has not been seen yet, and its activation will fail an |
| -- elaboration check. |
| |
| if Is_Task_Type (Desig_T) |
| and then Scope (Base_Type (Desig_T)) = Current_Scope |
| and then Is_Compilation_Unit (Current_Scope) |
| and then Ekind (Current_Scope) = E_Package |
| and then not In_Package_Body (Current_Scope) |
| then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_N ("cannot activate task before body seen<<", N); |
| Error_Msg_N ("\Program_Error [<<", N); |
| end if; |
| |
| -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a |
| -- type with a task component on a subpool. This action must raise |
| -- Program_Error at runtime. |
| |
| if Ada_Version >= Ada_2012 |
| and then Nkind (N) = N_Allocator |
| and then Present (Subpool_Handle_Name (N)) |
| and then Has_Task (Desig_T) |
| then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_N ("cannot allocate task on subpool<<", N); |
| Error_Msg_N ("\Program_Error [<<", N); |
| |
| Rewrite (N, |
| Make_Raise_Program_Error (Sloc (N), |
| Reason => PE_Explicit_Raise)); |
| Set_Etype (N, Typ); |
| end if; |
| end Resolve_Allocator; |
| |
| --------------------------- |
| -- Resolve_Arithmetic_Op -- |
| --------------------------- |
| |
| -- Used for resolving all arithmetic operators except exponentiation |
| |
| procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| TL : constant Entity_Id := Base_Type (Etype (L)); |
| TR : constant Entity_Id := Base_Type (Etype (R)); |
| T : Entity_Id; |
| Rop : Node_Id; |
| |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| -- We do the resolution using the base type, because intermediate values |
| -- in expressions always are of the base type, not a subtype of it. |
| |
| function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean; |
| -- Returns True if N is in a context that expects "any real type" |
| |
| function Is_Integer_Or_Universal (N : Node_Id) return Boolean; |
| -- Return True iff given type is Integer or universal real/integer |
| |
| procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id); |
| -- Choose type of integer literal in fixed-point operation to conform |
| -- to available fixed-point type. T is the type of the other operand, |
| -- which is needed to determine the expected type of N. |
| |
| procedure Set_Operand_Type (N : Node_Id); |
| -- Set operand type to T if universal |
| |
| ------------------------------- |
| -- Expected_Type_Is_Any_Real -- |
| ------------------------------- |
| |
| function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is |
| begin |
| -- N is the expression after "delta" in a fixed_point_definition; |
| -- see RM-3.5.9(6): |
| |
| return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition, |
| N_Decimal_Fixed_Point_Definition, |
| |
| -- N is one of the bounds in a real_range_specification; |
| -- see RM-3.5.7(5): |
| |
| N_Real_Range_Specification, |
| |
| -- N is the expression of a delta_constraint; |
| -- see RM-J.3(3): |
| |
| N_Delta_Constraint); |
| end Expected_Type_Is_Any_Real; |
| |
| ----------------------------- |
| -- Is_Integer_Or_Universal -- |
| ----------------------------- |
| |
| function Is_Integer_Or_Universal (N : Node_Id) return Boolean is |
| T : Entity_Id; |
| Index : Interp_Index; |
| It : Interp; |
| |
| begin |
| if not Is_Overloaded (N) then |
| T := Etype (N); |
| return Base_Type (T) = Base_Type (Standard_Integer) |
| or else T = Universal_Integer |
| or else T = Universal_Real; |
| else |
| Get_First_Interp (N, Index, It); |
| while Present (It.Typ) loop |
| if Base_Type (It.Typ) = Base_Type (Standard_Integer) |
| or else It.Typ = Universal_Integer |
| or else It.Typ = Universal_Real |
| then |
| return True; |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| end if; |
| |
| return False; |
| end Is_Integer_Or_Universal; |
| |
| ---------------------------- |
| -- Set_Mixed_Mode_Operand -- |
| ---------------------------- |
| |
| procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is |
| Index : Interp_Index; |
| It : Interp; |
| |
| begin |
| if Universal_Interpretation (N) = Universal_Integer then |
| |
| -- A universal integer literal is resolved as standard integer |
| -- except in the case of a fixed-point result, where we leave it |
| -- as universal (to be handled by Exp_Fixd later on) |
| |
| if Is_Fixed_Point_Type (T) then |
| Resolve (N, Universal_Integer); |
| else |
| Resolve (N, Standard_Integer); |
| end if; |
| |
| elsif Universal_Interpretation (N) = Universal_Real |
| and then (T = Base_Type (Standard_Integer) |
| or else T = Universal_Integer |
| or else T = Universal_Real) |
| then |
| -- A universal real can appear in a fixed-type context. We resolve |
| -- the literal with that context, even though this might raise an |
| -- exception prematurely (the other operand may be zero). |
| |
| Resolve (N, B_Typ); |
| |
| elsif Etype (N) = Base_Type (Standard_Integer) |
| and then T = Universal_Real |
| and then Is_Overloaded (N) |
| then |
| -- Integer arg in mixed-mode operation. Resolve with universal |
| -- type, in case preference rule must be applied. |
| |
| Resolve (N, Universal_Integer); |
| |
| elsif Etype (N) = T |
| and then B_Typ /= Universal_Fixed |
| then |
| -- Not a mixed-mode operation, resolve with context |
| |
| Resolve (N, B_Typ); |
| |
| elsif Etype (N) = Any_Fixed then |
| |
| -- N may itself be a mixed-mode operation, so use context type |
| |
| Resolve (N, B_Typ); |
| |
| elsif Is_Fixed_Point_Type (T) |
| and then B_Typ = Universal_Fixed |
| and then Is_Overloaded (N) |
| then |
| -- Must be (fixed * fixed) operation, operand must have one |
| -- compatible interpretation. |
| |
| Resolve (N, Any_Fixed); |
| |
| elsif Is_Fixed_Point_Type (B_Typ) |
| and then (T = Universal_Real or else Is_Fixed_Point_Type (T)) |
| and then Is_Overloaded (N) |
| then |
| -- C * F(X) in a fixed context, where C is a real literal or a |
| -- fixed-point expression. F must have either a fixed type |
| -- interpretation or an integer interpretation, but not both. |
| |
| Get_First_Interp (N, Index, It); |
| while Present (It.Typ) loop |
| if Base_Type (It.Typ) = Base_Type (Standard_Integer) then |
| if Analyzed (N) then |
| Error_Msg_N ("ambiguous operand in fixed operation", N); |
| else |
| Resolve (N, Standard_Integer); |
| end if; |
| |
| elsif Is_Fixed_Point_Type (It.Typ) then |
| if Analyzed (N) then |
| Error_Msg_N ("ambiguous operand in fixed operation", N); |
| else |
| Resolve (N, It.Typ); |
| end if; |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| |
| -- Reanalyze the literal with the fixed type of the context. If |
| -- context is Universal_Fixed, we are within a conversion, leave |
| -- the literal as a universal real because there is no usable |
| -- fixed type, and the target of the conversion plays no role in |
| -- the resolution. |
| |
| declare |
| Op2 : Node_Id; |
| T2 : Entity_Id; |
| |
| begin |
| if N = L then |
| Op2 := R; |
| else |
| Op2 := L; |
| end if; |
| |
| if B_Typ = Universal_Fixed |
| and then Nkind (Op2) = N_Real_Literal |
| then |
| T2 := Universal_Real; |
| else |
| T2 := B_Typ; |
| end if; |
| |
| Set_Analyzed (Op2, False); |
| Resolve (Op2, T2); |
| end; |
| |
| else |
| Resolve (N); |
| end if; |
| end Set_Mixed_Mode_Operand; |
| |
| ---------------------- |
| -- Set_Operand_Type -- |
| ---------------------- |
| |
| procedure Set_Operand_Type (N : Node_Id) is |
| begin |
| if Etype (N) = Universal_Integer |
| or else Etype (N) = Universal_Real |
| then |
| Set_Etype (N, T); |
| end if; |
| end Set_Operand_Type; |
| |
| -- Start of processing for Resolve_Arithmetic_Op |
| |
| begin |
| if Comes_From_Source (N) |
| and then Ekind (Entity (N)) = E_Function |
| and then Is_Imported (Entity (N)) |
| and then Is_Intrinsic_Subprogram (Entity (N)) |
| then |
| Resolve_Intrinsic_Operator (N, Typ); |
| return; |
| |
| -- Special-case for mixed-mode universal expressions or fixed point type |
| -- operation: each argument is resolved separately. The same treatment |
| -- is required if one of the operands of a fixed point operation is |
| -- universal real, since in this case we don't do a conversion to a |
| -- specific fixed-point type (instead the expander handles the case). |
| |
| -- Set the type of the node to its universal interpretation because |
| -- legality checks on an exponentiation operand need the context. |
| |
| elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real) |
| and then Present (Universal_Interpretation (L)) |
| and then Present (Universal_Interpretation (R)) |
| then |
| Set_Etype (N, B_Typ); |
| Resolve (L, Universal_Interpretation (L)); |
| Resolve (R, Universal_Interpretation (R)); |
| |
| elsif (B_Typ = Universal_Real |
| or else Etype (N) = Universal_Fixed |
| or else (Etype (N) = Any_Fixed |
| and then Is_Fixed_Point_Type (B_Typ)) |
| or else (Is_Fixed_Point_Type (B_Typ) |
| and then (Is_Integer_Or_Universal (L) |
| or else |
| Is_Integer_Or_Universal (R)))) |
| and then Nkind_In (N, N_Op_Multiply, N_Op_Divide) |
| then |
| if TL = Universal_Integer or else TR = Universal_Integer then |
| Check_For_Visible_Operator (N, B_Typ); |
| end if; |
| |
| -- If context is a fixed type and one operand is integer, the other |
| -- is resolved with the type of the context. |
| |
| if Is_Fixed_Point_Type (B_Typ) |
| and then (Base_Type (TL) = Base_Type (Standard_Integer) |
| or else TL = Universal_Integer) |
| then |
| Resolve (R, B_Typ); |
| Resolve (L, TL); |
| |
| elsif Is_Fixed_Point_Type (B_Typ) |
| and then (Base_Type (TR) = Base_Type (Standard_Integer) |
| or else TR = Universal_Integer) |
| then |
| Resolve (L, B_Typ); |
| Resolve (R, TR); |
| |
| else |
| Set_Mixed_Mode_Operand (L, TR); |
| Set_Mixed_Mode_Operand (R, TL); |
| end if; |
| |
| -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed |
| -- multiplying operators from being used when the expected type is |
| -- also universal_fixed. Note that B_Typ will be Universal_Fixed in |
| -- some cases where the expected type is actually Any_Real; |
| -- Expected_Type_Is_Any_Real takes care of that case. |
| |
| if Etype (N) = Universal_Fixed |
| or else Etype (N) = Any_Fixed |
| then |
| if B_Typ = Universal_Fixed |
| and then not Expected_Type_Is_Any_Real (N) |
| and then not Nkind_In (Parent (N), N_Type_Conversion, |
| N_Unchecked_Type_Conversion) |
| then |
| Error_Msg_N ("type cannot be determined from context!", N); |
| Error_Msg_N ("\explicit conversion to result type required", N); |
| |
| Set_Etype (L, Any_Type); |
| Set_Etype (R, Any_Type); |
| |
| else |
| if Ada_Version = Ada_83 |
| and then Etype (N) = Universal_Fixed |
| and then not |
| Nkind_In (Parent (N), N_Type_Conversion, |
| N_Unchecked_Type_Conversion) |
| then |
| Error_Msg_N |
| ("(Ada 83) fixed-point operation " |
| & "needs explicit conversion", N); |
| end if; |
| |
| -- The expected type is "any real type" in contexts like |
| |
| -- type T is delta <universal_fixed-expression> ... |
| |
| -- in which case we need to set the type to Universal_Real |
| -- so that static expression evaluation will work properly. |
| |
| if Expected_Type_Is_Any_Real (N) then |
| Set_Etype (N, Universal_Real); |
| else |
| Set_Etype (N, B_Typ); |
| end if; |
| end if; |
| |
| elsif Is_Fixed_Point_Type (B_Typ) |
| and then (Is_Integer_Or_Universal (L) |
| or else Nkind (L) = N_Real_Literal |
| or else Nkind (R) = N_Real_Literal |
| or else Is_Integer_Or_Universal (R)) |
| then |
| Set_Etype (N, B_Typ); |
| |
| elsif Etype (N) = Any_Fixed then |
| |
| -- If no previous errors, this is only possible if one operand is |
| -- overloaded and the context is universal. Resolve as such. |
| |
| Set_Etype (N, B_Typ); |
| end if; |
| |
| else |
| if (TL = Universal_Integer or else TL = Universal_Real) |
| and then |
| (TR = Universal_Integer or else TR = Universal_Real) |
| then |
| Check_For_Visible_Operator (N, B_Typ); |
| end if; |
| |
| -- If the context is Universal_Fixed and the operands are also |
| -- universal fixed, this is an error, unless there is only one |
| -- applicable fixed_point type (usually Duration). |
| |
| if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then |
| T := Unique_Fixed_Point_Type (N); |
| |
| if T = Any_Type then |
| Set_Etype (N, T); |
| return; |
| else |
| Resolve (L, T); |
| Resolve (R, T); |
| end if; |
| |
| else |
| Resolve (L, B_Typ); |
| Resolve (R, B_Typ); |
| end if; |
| |
| -- If one of the arguments was resolved to a non-universal type. |
| -- label the result of the operation itself with the same type. |
| -- Do the same for the universal argument, if any. |
| |
| T := Intersect_Types (L, R); |
| Set_Etype (N, Base_Type (T)); |
| Set_Operand_Type (L); |
| Set_Operand_Type (R); |
| end if; |
| |
| Generate_Operator_Reference (N, Typ); |
| Analyze_Dimension (N); |
| Eval_Arithmetic_Op (N); |
| |
| -- In SPARK, a multiplication or division with operands of fixed point |
| -- types shall be qualified or explicitly converted to identify the |
| -- result type. |
| |
| if (Is_Fixed_Point_Type (Etype (L)) |
| or else Is_Fixed_Point_Type (Etype (R))) |
| and then Nkind_In (N, N_Op_Multiply, N_Op_Divide) |
| and then |
| not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion) |
| then |
| Check_SPARK_Restriction |
| ("operation should be qualified or explicitly converted", N); |
| end if; |
| |
| -- Set overflow and division checking bit |
| |
| if Nkind (N) in N_Op then |
| if not Overflow_Checks_Suppressed (Etype (N)) then |
| Enable_Overflow_Check (N); |
| end if; |
| |
| -- Give warning if explicit division by zero |
| |
| if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod) |
| and then not Division_Checks_Suppressed (Etype (N)) |
| then |
| Rop := Right_Opnd (N); |
| |
| if Compile_Time_Known_Value (Rop) |
| and then ((Is_Integer_Type (Etype (Rop)) |
| and then Expr_Value (Rop) = Uint_0) |
| or else |
| (Is_Real_Type (Etype (Rop)) |
| and then Expr_Value_R (Rop) = Ureal_0)) |
| then |
| -- Specialize the warning message according to the operation. |
| -- The following warnings are for the case |
| |
| case Nkind (N) is |
| when N_Op_Divide => |
| |
| -- For division, we have two cases, for float division |
| -- of an unconstrained float type, on a machine where |
| -- Machine_Overflows is false, we don't get an exception |
| -- at run-time, but rather an infinity or Nan. The Nan |
| -- case is pretty obscure, so just warn about infinities. |
| |
| if Is_Floating_Point_Type (Typ) |
| and then not Is_Constrained (Typ) |
| and then not Machine_Overflows_On_Target |
| then |
| Error_Msg_N |
| ("float division by zero, may generate " |
| & "'+'/'- infinity??", Right_Opnd (N)); |
| |
| -- For all other cases, we get a Constraint_Error |
| |
| else |
| Apply_Compile_Time_Constraint_Error |
| (N, "division by zero??", CE_Divide_By_Zero, |
| Loc => Sloc (Right_Opnd (N))); |
| end if; |
| |
| when N_Op_Rem => |
| Apply_Compile_Time_Constraint_Error |
| (N, "rem with zero divisor??", CE_Divide_By_Zero, |
| Loc => Sloc (Right_Opnd (N))); |
| |
| when N_Op_Mod => |
| Apply_Compile_Time_Constraint_Error |
| (N, "mod with zero divisor??", CE_Divide_By_Zero, |
| Loc => Sloc (Right_Opnd (N))); |
| |
| -- Division by zero can only happen with division, rem, |
| -- and mod operations. |
| |
| when others => |
| raise Program_Error; |
| end case; |
| |
| -- Otherwise just set the flag to check at run time |
| |
| else |
| Activate_Division_Check (N); |
| end if; |
| end if; |
| |
| -- If Restriction No_Implicit_Conditionals is active, then it is |
| -- violated if either operand can be negative for mod, or for rem |
| -- if both operands can be negative. |
| |
| if Restriction_Check_Required (No_Implicit_Conditionals) |
| and then Nkind_In (N, N_Op_Rem, N_Op_Mod) |
| then |
| declare |
| Lo : Uint; |
| Hi : Uint; |
| OK : Boolean; |
| |
| LNeg : Boolean; |
| RNeg : Boolean; |
| -- Set if corresponding operand might be negative |
| |
| begin |
| Determine_Range |
| (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True); |
| LNeg := (not OK) or else Lo < 0; |
| |
| Determine_Range |
| (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True); |
| RNeg := (not OK) or else Lo < 0; |
| |
| -- Check if we will be generating conditionals. There are two |
| -- cases where that can happen, first for REM, the only case |
| -- is largest negative integer mod -1, where the division can |
| -- overflow, but we still have to give the right result. The |
| -- front end generates a test for this annoying case. Here we |
| -- just test if both operands can be negative (that's what the |
| -- expander does, so we match its logic here). |
| |
| -- The second case is mod where either operand can be negative. |
| -- In this case, the back end has to generate additional tests. |
| |
| if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg)) |
| or else |
| (Nkind (N) = N_Op_Mod and then (LNeg or RNeg)) |
| then |
| Check_Restriction (No_Implicit_Conditionals, N); |
| end if; |
| end; |
| end if; |
| end if; |
| |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (R); |
| Check_Function_Writable_Actuals (N); |
| end Resolve_Arithmetic_Op; |
| |
| ------------------ |
| -- Resolve_Call -- |
| ------------------ |
| |
| procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Subp : constant Node_Id := Name (N); |
| Nam : Entity_Id; |
| I : Interp_Index; |
| It : Interp; |
| Norm_OK : Boolean; |
| Scop : Entity_Id; |
| Rtype : Entity_Id; |
| |
| function Same_Or_Aliased_Subprograms |
| (S : Entity_Id; |
| E : Entity_Id) return Boolean; |
| -- Returns True if the subprogram entity S is the same as E or else |
| -- S is an alias of E. |
| |
| --------------------------------- |
| -- Same_Or_Aliased_Subprograms -- |
| --------------------------------- |
| |
| function Same_Or_Aliased_Subprograms |
| (S : Entity_Id; |
| E : Entity_Id) return Boolean |
| is |
| Subp_Alias : constant Entity_Id := Alias (S); |
| begin |
| return S = E or else (Present (Subp_Alias) and then Subp_Alias = E); |
| end Same_Or_Aliased_Subprograms; |
| |
| -- Start of processing for Resolve_Call |
| |
| begin |
| -- The context imposes a unique interpretation with type Typ on a |
| -- procedure or function call. Find the entity of the subprogram that |
| -- yields the expected type, and propagate the corresponding formal |
| -- constraints on the actuals. The caller has established that an |
| -- interpretation exists, and emitted an error if not unique. |
| |
| -- First deal with the case of a call to an access-to-subprogram, |
| -- dereference made explicit in Analyze_Call. |
| |
| if Ekind (Etype (Subp)) = E_Subprogram_Type then |
| if not Is_Overloaded (Subp) then |
| Nam := Etype (Subp); |
| |
| else |
| -- Find the interpretation whose type (a subprogram type) has a |
| -- return type that is compatible with the context. Analysis of |
| -- the node has established that one exists. |
| |
| Nam := Empty; |
| |
| Get_First_Interp (Subp, I, It); |
| while Present (It.Typ) loop |
| if Covers (Typ, Etype (It.Typ)) then |
| Nam := It.Typ; |
| exit; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| if No (Nam) then |
| raise Program_Error; |
| end if; |
| end if; |
| |
| -- If the prefix is not an entity, then resolve it |
| |
| if not Is_Entity_Name (Subp) then |
| Resolve (Subp, Nam); |
| end if; |
| |
| -- For an indirect call, we always invalidate checks, since we do not |
| -- know whether the subprogram is local or global. Yes we could do |
| -- better here, e.g. by knowing that there are no local subprograms, |
| -- but it does not seem worth the effort. Similarly, we kill all |
| -- knowledge of current constant values. |
| |
| Kill_Current_Values; |
| |
| -- If this is a procedure call which is really an entry call, do |
| -- the conversion of the procedure call to an entry call. Protected |
| -- operations use the same circuitry because the name in the call |
| -- can be an arbitrary expression with special resolution rules. |
| |
| elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component) |
| or else (Is_Entity_Name (Subp) |
| and then Ekind (Entity (Subp)) = E_Entry) |
| then |
| Resolve_Entry_Call (N, Typ); |
| Check_Elab_Call (N); |
| |
| -- Kill checks and constant values, as above for indirect case |
| -- Who knows what happens when another task is activated? |
| |
| Kill_Current_Values; |
| return; |
| |
| -- Normal subprogram call with name established in Resolve |
| |
| elsif not (Is_Type (Entity (Subp))) then |
| Nam := Entity (Subp); |
| Set_Entity_With_Checks (Subp, Nam); |
| |
| -- Otherwise we must have the case of an overloaded call |
| |
| else |
| pragma Assert (Is_Overloaded (Subp)); |
| |
| -- Initialize Nam to prevent warning (we know it will be assigned |
| -- in the loop below, but the compiler does not know that). |
| |
| Nam := Empty; |
| |
| Get_First_Interp (Subp, I, It); |
| while Present (It.Typ) loop |
| if Covers (Typ, It.Typ) then |
| Nam := It.Nam; |
| Set_Entity_With_Checks (Subp, Nam); |
| exit; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end if; |
| |
| if Is_Access_Subprogram_Type (Base_Type (Etype (Nam))) |
| and then not Is_Access_Subprogram_Type (Base_Type (Typ)) |
| and then Nkind (Subp) /= N_Explicit_Dereference |
| and then Present (Parameter_Associations (N)) |
| then |
| -- The prefix is a parameterless function call that returns an access |
| -- to subprogram. If parameters are present in the current call, add |
| -- add an explicit dereference. We use the base type here because |
| -- within an instance these may be subtypes. |
| |
| -- The dereference is added either in Analyze_Call or here. Should |
| -- be consolidated ??? |
| |
| Set_Is_Overloaded (Subp, False); |
| Set_Etype (Subp, Etype (Nam)); |
| Insert_Explicit_Dereference (Subp); |
| Nam := Designated_Type (Etype (Nam)); |
| Resolve (Subp, Nam); |
| end if; |
| |
| -- Check that a call to Current_Task does not occur in an entry body |
| |
| if Is_RTE (Nam, RE_Current_Task) then |
| declare |
| P : Node_Id; |
| |
| begin |
| P := N; |
| loop |
| P := Parent (P); |
| |
| -- Exclude calls that occur within the default of a formal |
| -- parameter of the entry, since those are evaluated outside |
| -- of the body. |
| |
| exit when No (P) or else Nkind (P) = N_Parameter_Specification; |
| |
| if Nkind (P) = N_Entry_Body |
| or else (Nkind (P) = N_Subprogram_Body |
| and then Is_Entry_Barrier_Function (P)) |
| then |
| Rtype := Etype (N); |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_NE |
| ("& should not be used in entry body (RM C.7(17))<<", |
| N, Nam); |
| Error_Msg_NE ("\Program_Error [<<", N, Nam); |
| Rewrite (N, |
| Make_Raise_Program_Error (Loc, |
| Reason => PE_Current_Task_In_Entry_Body)); |
| Set_Etype (N, Rtype); |
| return; |
| end if; |
| end loop; |
| end; |
| end if; |
| |
| -- Check that a procedure call does not occur in the context of the |
| -- entry call statement of a conditional or timed entry call. Note that |
| -- the case of a call to a subprogram renaming of an entry will also be |
| -- rejected. The test for N not being an N_Entry_Call_Statement is |
| -- defensive, covering the possibility that the processing of entry |
| -- calls might reach this point due to later modifications of the code |
| -- above. |
| |
| if Nkind (Parent (N)) = N_Entry_Call_Alternative |
| and then Nkind (N) /= N_Entry_Call_Statement |
| and then Entry_Call_Statement (Parent (N)) = N |
| then |
| if Ada_Version < Ada_2005 then |
| Error_Msg_N ("entry call required in select statement", N); |
| |
| -- Ada 2005 (AI-345): If a procedure_call_statement is used |
| -- for a procedure_or_entry_call, the procedure_name or |
| -- procedure_prefix of the procedure_call_statement shall denote |
| -- an entry renamed by a procedure, or (a view of) a primitive |
| -- subprogram of a limited interface whose first parameter is |
| -- a controlling parameter. |
| |
| elsif Nkind (N) = N_Procedure_Call_Statement |
| and then not Is_Renamed_Entry (Nam) |
| and then not Is_Controlling_Limited_Procedure (Nam) |
| then |
| Error_Msg_N |
| ("entry call or dispatching primitive of interface required", N); |
| end if; |
| end if; |
| |
| -- If the SPARK_05 restriction is active, we are not allowed |
| -- to have a call to a subprogram before we see its completion. |
| |
| if not Has_Completion (Nam) |
| and then Restriction_Check_Required (SPARK_05) |
| |
| -- Don't flag strange internal calls |
| |
| and then Comes_From_Source (N) |
| and then Comes_From_Source (Nam) |
| |
| -- Only flag calls in extended main source |
| |
| and then In_Extended_Main_Source_Unit (Nam) |
| and then In_Extended_Main_Source_Unit (N) |
| |
| -- Exclude enumeration literals from this processing |
| |
| and then Ekind (Nam) /= E_Enumeration_Literal |
| then |
| Check_SPARK_Restriction |
| ("call to subprogram cannot appear before its body", N); |
| end if; |
| |
| -- Check that this is not a call to a protected procedure or entry from |
| -- within a protected function. |
| |
| Check_Internal_Protected_Use (N, Nam); |
| |
| -- Freeze the subprogram name if not in a spec-expression. Note that |
| -- we freeze procedure calls as well as function calls. Procedure calls |
| -- are not frozen according to the rules (RM 13.14(14)) because it is |
| -- impossible to have a procedure call to a non-frozen procedure in |
| -- pure Ada, but in the code that we generate in the expander, this |
| -- rule needs extending because we can generate procedure calls that |
| -- need freezing. |
| |
| -- In Ada 2012, expression functions may be called within pre/post |
| -- conditions of subsequent functions or expression functions. Such |
| -- calls do not freeze when they appear within generated bodies, |
| -- (including the body of another expression function) which would |
| -- place the freeze node in the wrong scope. An expression function |
| -- is frozen in the usual fashion, by the appearance of a real body, |
| -- or at the end of a declarative part. |
| |
| if Is_Entity_Name (Subp) and then not In_Spec_Expression |
| and then not Is_Expression_Function (Current_Scope) |
| and then |
| (not Is_Expression_Function (Entity (Subp)) |
| or else Scope (Entity (Subp)) = Current_Scope) |
| then |
| Freeze_Expression (Subp); |
| end if; |
| |
| -- For a predefined operator, the type of the result is the type imposed |
| -- by context, except for a predefined operation on universal fixed. |
| -- Otherwise The type of the call is the type returned by the subprogram |
| -- being called. |
| |
| if Is_Predefined_Op (Nam) then |
| if Etype (N) /= Universal_Fixed then |
| Set_Etype (N, Typ); |
| end if; |
| |
| -- If the subprogram returns an array type, and the context requires the |
| -- component type of that array type, the node is really an indexing of |
| -- the parameterless call. Resolve as such. A pathological case occurs |
| -- when the type of the component is an access to the array type. In |
| -- this case the call is truly ambiguous. |
| |
| elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam)) |
| and then |
| ((Is_Array_Type (Etype (Nam)) |
| and then Covers (Typ, Component_Type (Etype (Nam)))) |
| or else |
| (Is_Access_Type (Etype (Nam)) |
| and then Is_Array_Type (Designated_Type (Etype (Nam))) |
| and then |
| Covers (Typ, Component_Type (Designated_Type (Etype (Nam)))))) |
| then |
| declare |
| Index_Node : Node_Id; |
| New_Subp : Node_Id; |
| Ret_Type : constant Entity_Id := Etype (Nam); |
| |
| begin |
| if Is_Access_Type (Ret_Type) |
| and then Ret_Type = Component_Type (Designated_Type (Ret_Type)) |
| then |
| Error_Msg_N |
| ("cannot disambiguate function call and indexing", N); |
| else |
| New_Subp := Relocate_Node (Subp); |
| |
| -- The called entity may be an explicit dereference, in which |
| -- case there is no entity to set. |
| |
| if Nkind (New_Subp) /= N_Explicit_Dereference then |
| Set_Entity (Subp, Nam); |
| end if; |
| |
| if (Is_Array_Type (Ret_Type) |
| and then Component_Type (Ret_Type) /= Any_Type) |
| or else |
| (Is_Access_Type (Ret_Type) |
| and then |
| Component_Type (Designated_Type (Ret_Type)) /= Any_Type) |
| then |
| if Needs_No_Actuals (Nam) then |
| |
| -- Indexed call to a parameterless function |
| |
| Index_Node := |
| Make_Indexed_Component (Loc, |
| Prefix => |
| Make_Function_Call (Loc, |
| Name => New_Subp), |
| Expressions => Parameter_Associations (N)); |
| else |
| -- An Ada 2005 prefixed call to a primitive operation |
| -- whose first parameter is the prefix. This prefix was |
| -- prepended to the parameter list, which is actually a |
| -- list of indexes. Remove the prefix in order to build |
| -- the proper indexed component. |
| |
| Index_Node := |
| Make_Indexed_Component (Loc, |
| Prefix => |
| Make_Function_Call (Loc, |
| Name => New_Subp, |
| Parameter_Associations => |
| New_List |
| (Remove_Head (Parameter_Associations (N)))), |
| Expressions => Parameter_Associations (N)); |
| end if; |
| |
| -- Preserve the parenthesis count of the node |
| |
| Set_Paren_Count (Index_Node, Paren_Count (N)); |
| |
| -- Since we are correcting a node classification error made |
| -- by the parser, we call Replace rather than Rewrite. |
| |
| Replace (N, Index_Node); |
| |
| Set_Etype (Prefix (N), Ret_Type); |
| Set_Etype (N, Typ); |
| Resolve_Indexed_Component (N, Typ); |
| Check_Elab_Call (Prefix (N)); |
| end if; |
| end if; |
| |
| return; |
| end; |
| |
| else |
| Set_Etype (N, Etype (Nam)); |
| end if; |
| |
| -- In the case where the call is to an overloaded subprogram, Analyze |
| -- calls Normalize_Actuals once per overloaded subprogram. Therefore in |
| -- such a case Normalize_Actuals needs to be called once more to order |
| -- the actuals correctly. Otherwise the call will have the ordering |
| -- given by the last overloaded subprogram whether this is the correct |
| -- one being called or not. |
| |
| if Is_Overloaded (Subp) then |
| Normalize_Actuals (N, Nam, False, Norm_OK); |
| pragma Assert (Norm_OK); |
| end if; |
| |
| -- In any case, call is fully resolved now. Reset Overload flag, to |
| -- prevent subsequent overload resolution if node is analyzed again |
| |
| Set_Is_Overloaded (Subp, False); |
| Set_Is_Overloaded (N, False); |
| |
| -- If we are calling the current subprogram from immediately within its |
| -- body, then that is the case where we can sometimes detect cases of |
| -- infinite recursion statically. Do not try this in case restriction |
| -- No_Recursion is in effect anyway, and do it only for source calls. |
| |
| if Comes_From_Source (N) then |
| Scop := Current_Scope; |
| |
| -- Check violation of SPARK_05 restriction which does not permit |
| -- a subprogram body to contain a call to the subprogram directly. |
| |
| if Restriction_Check_Required (SPARK_05) |
| and then Same_Or_Aliased_Subprograms (Nam, Scop) |
| then |
| Check_SPARK_Restriction |
| ("subprogram may not contain direct call to itself", N); |
| end if; |
| |
| -- Issue warning for possible infinite recursion in the absence |
| -- of the No_Recursion restriction. |
| |
| if Same_Or_Aliased_Subprograms (Nam, Scop) |
| and then not Restriction_Active (No_Recursion) |
| and then Check_Infinite_Recursion (N) |
| then |
| -- Here we detected and flagged an infinite recursion, so we do |
| -- not need to test the case below for further warnings. Also we |
| -- are all done if we now have a raise SE node. |
| |
| if Nkind (N) = N_Raise_Storage_Error then |
| return; |
| end if; |
| |
| -- If call is to immediately containing subprogram, then check for |
| -- the case of a possible run-time detectable infinite recursion. |
| |
| else |
| Scope_Loop : while Scop /= Standard_Standard loop |
| if Same_Or_Aliased_Subprograms (Nam, Scop) then |
| |
| -- Although in general case, recursion is not statically |
| -- checkable, the case of calling an immediately containing |
| -- subprogram is easy to catch. |
| |
| Check_Restriction (No_Recursion, N); |
| |
| -- If the recursive call is to a parameterless subprogram, |
| -- then even if we can't statically detect infinite |
| -- recursion, this is pretty suspicious, and we output a |
| -- warning. Furthermore, we will try later to detect some |
| -- cases here at run time by expanding checking code (see |
| -- Detect_Infinite_Recursion in package Exp_Ch6). |
| |
| -- If the recursive call is within a handler, do not emit a |
| -- warning, because this is a common idiom: loop until input |
| -- is correct, catch illegal input in handler and restart. |
| |
| if No (First_Formal (Nam)) |
| and then Etype (Nam) = Standard_Void_Type |
| and then not Error_Posted (N) |
| and then Nkind (Parent (N)) /= N_Exception_Handler |
| then |
| -- For the case of a procedure call. We give the message |
| -- only if the call is the first statement in a sequence |
| -- of statements, or if all previous statements are |
| -- simple assignments. This is simply a heuristic to |
| -- decrease false positives, without losing too many good |
| -- warnings. The idea is that these previous statements |
| -- may affect global variables the procedure depends on. |
| -- We also exclude raise statements, that may arise from |
| -- constraint checks and are probably unrelated to the |
| -- intended control flow. |
| |
| if Nkind (N) = N_Procedure_Call_Statement |
| and then Is_List_Member (N) |
| then |
| declare |
| P : Node_Id; |
| begin |
| P := Prev (N); |
| while Present (P) loop |
| if not Nkind_In (P, |
| N_Assignment_Statement, |
| N_Raise_Constraint_Error) |
| then |
| exit Scope_Loop; |
| end if; |
| |
| Prev (P); |
| end loop; |
| end; |
| end if; |
| |
| -- Do not give warning if we are in a conditional context |
| |
| declare |
| K : constant Node_Kind := Nkind (Parent (N)); |
| begin |
| if (K = N_Loop_Statement |
| and then Present (Iteration_Scheme (Parent (N)))) |
| or else K = N_If_Statement |
| or else K = N_Elsif_Part |
| or else K = N_Case_Statement_Alternative |
| then |
| exit Scope_Loop; |
| end if; |
| end; |
| |
| -- Here warning is to be issued |
| |
| Set_Has_Recursive_Call (Nam); |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_N ("possible infinite recursion<<!", N); |
| Error_Msg_N ("\Storage_Error ]<<!", N); |
| end if; |
| |
| exit Scope_Loop; |
| end if; |
| |
| Scop := Scope (Scop); |
| end loop Scope_Loop; |
| end if; |
| end if; |
| |
| -- Check obsolescent reference to Ada.Characters.Handling subprogram |
| |
| Check_Obsolescent_2005_Entity (Nam, Subp); |
| |
| -- If subprogram name is a predefined operator, it was given in |
| -- functional notation. Replace call node with operator node, so |
| -- that actuals can be resolved appropriately. |
| |
| if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then |
| Make_Call_Into_Operator (N, Typ, Entity (Name (N))); |
| return; |
| |
| elsif Present (Alias (Nam)) |
| and then Is_Predefined_Op (Alias (Nam)) |
| then |
| Resolve_Actuals (N, Nam); |
| Make_Call_Into_Operator (N, Typ, Alias (Nam)); |
| return; |
| end if; |
| |
| -- Create a transient scope if the resulting type requires it |
| |
| -- There are several notable exceptions: |
| |
| -- a) In init procs, the transient scope overhead is not needed, and is |
| -- even incorrect when the call is a nested initialization call for a |
| -- component whose expansion may generate adjust calls. However, if the |
| -- call is some other procedure call within an initialization procedure |
| -- (for example a call to Create_Task in the init_proc of the task |
| -- run-time record) a transient scope must be created around this call. |
| |
| -- b) Enumeration literal pseudo-calls need no transient scope |
| |
| -- c) Intrinsic subprograms (Unchecked_Conversion and source info |
| -- functions) do not use the secondary stack even though the return |
| -- type may be unconstrained. |
| |
| -- d) Calls to a build-in-place function, since such functions may |
| -- allocate their result directly in a target object, and cases where |
| -- the result does get allocated in the secondary stack are checked for |
| -- within the specialized Exp_Ch6 procedures for expanding those |
| -- build-in-place calls. |
| |
| -- e) If the subprogram is marked Inline_Always, then even if it returns |
| -- an unconstrained type the call does not require use of the secondary |
| -- stack. However, inlining will only take place if the body to inline |
| -- is already present. It may not be available if e.g. the subprogram is |
| -- declared in a child instance. |
| |
| -- If this is an initialization call for a type whose construction |
| -- uses the secondary stack, and it is not a nested call to initialize |
| -- a component, we do need to create a transient scope for it. We |
| -- check for this by traversing the type in Check_Initialization_Call. |
| |
| if Is_Inlined (Nam) |
| and then Has_Pragma_Inline_Always (Nam) |
| and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration |
| and then Present (Body_To_Inline (Unit_Declaration_Node (Nam))) |
| and then not Debug_Flag_Dot_K |
| then |
| null; |
| |
| elsif Is_Inlined (Nam) |
| and then Has_Pragma_Inline (Nam) |
| and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration |
| and then Present (Body_To_Inline (Unit_Declaration_Node (Nam))) |
| and then Debug_Flag_Dot_K |
| then |
| null; |
| |
| elsif Ekind (Nam) = E_Enumeration_Literal |
| or else Is_Build_In_Place_Function (Nam) |
| or else Is_Intrinsic_Subprogram (Nam) |
| then |
| null; |
| |
| elsif Expander_Active |
| and then Is_Type (Etype (Nam)) |
| and then Requires_Transient_Scope (Etype (Nam)) |
| and then |
| (not Within_Init_Proc |
| or else |
| (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function)) |
| then |
| Establish_Transient_Scope (N, Sec_Stack => True); |
| |
| -- If the call appears within the bounds of a loop, it will |
| -- be rewritten and reanalyzed, nothing left to do here. |
| |
| if Nkind (N) /= N_Function_Call then |
| return; |
| end if; |
| |
| elsif Is_Init_Proc (Nam) |
| and then not Within_Init_Proc |
| then |
| Check_Initialization_Call (N, Nam); |
| end if; |
| |
| -- A protected function cannot be called within the definition of the |
| -- enclosing protected type. |
| |
| if Is_Protected_Type (Scope (Nam)) |
| and then In_Open_Scopes (Scope (Nam)) |
| and then not Has_Completion (Scope (Nam)) |
| then |
| Error_Msg_NE |
| ("& cannot be called before end of protected definition", N, Nam); |
| end if; |
| |
| -- Propagate interpretation to actuals, and add default expressions |
| -- where needed. |
| |
| if Present (First_Formal (Nam)) then |
| Resolve_Actuals (N, Nam); |
| |
| -- Overloaded literals are rewritten as function calls, for purpose of |
| -- resolution. After resolution, we can replace the call with the |
| -- literal itself. |
| |
| elsif Ekind (Nam) = E_Enumeration_Literal then |
| Copy_Node (Subp, N); |
| Resolve_Entity_Name (N, Typ); |
| |
| -- Avoid validation, since it is a static function call |
| |
| Generate_Reference (Nam, Subp); |
| return; |
| end if; |
| |
| -- If the subprogram is not global, then kill all saved values and |
| -- checks. This is a bit conservative, since in many cases we could do |
| -- better, but it is not worth the effort. Similarly, we kill constant |
| -- values. However we do not need to do this for internal entities |
| -- (unless they are inherited user-defined subprograms), since they |
| -- are not in the business of molesting local values. |
| |
| -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also |
| -- kill all checks and values for calls to global subprograms. This |
| -- takes care of the case where an access to a local subprogram is |
| -- taken, and could be passed directly or indirectly and then called |
| -- from almost any context. |
| |
| -- Note: we do not do this step till after resolving the actuals. That |
| -- way we still take advantage of the current value information while |
| -- scanning the actuals. |
| |
| -- We suppress killing values if we are processing the nodes associated |
| -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged |
| -- type kills all the values as part of analyzing the code that |
| -- initializes the dispatch tables. |
| |
| if Inside_Freezing_Actions = 0 |
| and then (not Is_Library_Level_Entity (Nam) |
| or else Suppress_Value_Tracking_On_Call |
| (Nearest_Dynamic_Scope (Current_Scope))) |
| and then (Comes_From_Source (Nam) |
| or else (Present (Alias (Nam)) |
| and then Comes_From_Source (Alias (Nam)))) |
| then |
| Kill_Current_Values; |
| end if; |
| |
| -- If we are warning about unread OUT parameters, this is the place to |
| -- set Last_Assignment for OUT and IN OUT parameters. We have to do this |
| -- after the above call to Kill_Current_Values (since that call clears |
| -- the Last_Assignment field of all local variables). |
| |
| if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters) |
| and then Comes_From_Source (N) |
| and then In_Extended_Main_Source_Unit (N) |
| then |
| declare |
| F : Entity_Id; |
| A : Node_Id; |
| |
| begin |
| F := First_Formal (Nam); |
| A := First_Actual (N); |
| while Present (F) and then Present (A) loop |
| if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) |
| and then Warn_On_Modified_As_Out_Parameter (F) |
| and then Is_Entity_Name (A) |
| and then Present (Entity (A)) |
| and then Comes_From_Source (N) |
| and then Safe_To_Capture_Value (N, Entity (A)) |
| then |
| Set_Last_Assignment (Entity (A), A); |
| end if; |
| |
| Next_Formal (F); |
| Next_Actual (A); |
| end loop; |
| end; |
| end if; |
| |
| -- If the subprogram is a primitive operation, check whether or not |
| -- it is a correct dispatching call. |
| |
| if Is_Overloadable (Nam) |
| and then Is_Dispatching_Operation (Nam) |
| then |
| Check_Dispatching_Call (N); |
| |
| elsif Ekind (Nam) /= E_Subprogram_Type |
| and then Is_Abstract_Subprogram (Nam) |
| and then not In_Instance |
| then |
| Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam); |
| end if; |
| |
| -- If this is a dispatching call, generate the appropriate reference, |
| -- for better source navigation in GPS. |
| |
| if Is_Overloadable (Nam) |
| and then Present (Controlling_Argument (N)) |
| then |
| Generate_Reference (Nam, Subp, 'R'); |
| |
| -- Normal case, not a dispatching call: generate a call reference |
| |
| else |
| Generate_Reference (Nam, Subp, 's'); |
| end if; |
| |
| if Is_Intrinsic_Subprogram (Nam) then |
| Check_Intrinsic_Call (N); |
| end if; |
| |
| -- Check for violation of restriction No_Specific_Termination_Handlers |
| -- and warn on a potentially blocking call to Abort_Task. |
| |
| if Restriction_Check_Required (No_Specific_Termination_Handlers) |
| and then (Is_RTE (Nam, RE_Set_Specific_Handler) |
| or else |
| Is_RTE (Nam, RE_Specific_Handler)) |
| then |
| Check_Restriction (No_Specific_Termination_Handlers, N); |
| |
| elsif Is_RTE (Nam, RE_Abort_Task) then |
| Check_Potentially_Blocking_Operation (N); |
| end if; |
| |
| -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative |
| -- timing event violates restriction No_Relative_Delay (AI-0211). We |
| -- need to check the second argument to determine whether it is an |
| -- absolute or relative timing event. |
| |
| if Restriction_Check_Required (No_Relative_Delay) |
| and then Is_RTE (Nam, RE_Set_Handler) |
| and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span) |
| then |
| Check_Restriction (No_Relative_Delay, N); |
| end if; |
| |
| -- Issue an error for a call to an eliminated subprogram. This routine |
| -- will not perform the check if the call appears within a default |
| -- expression. |
| |
| Check_For_Eliminated_Subprogram (Subp, Nam); |
| |
| -- In formal mode, the primitive operations of a tagged type or type |
| -- extension do not include functions that return the tagged type. |
| |
| if Nkind (N) = N_Function_Call |
| and then Is_Tagged_Type (Etype (N)) |
| and then Is_Entity_Name (Name (N)) |
| and then Is_Inherited_Operation_For_Type (Entity (Name (N)), Etype (N)) |
| then |
| Check_SPARK_Restriction ("function not inherited", N); |
| end if; |
| |
| -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is |
| -- class-wide and the call dispatches on result in a context that does |
| -- not provide a tag, the call raises Program_Error. |
| |
| if Nkind (N) = N_Function_Call |
| and then In_Instance |
| and then Is_Generic_Actual_Type (Typ) |
| and then Is_Class_Wide_Type (Typ) |
| and then Has_Controlling_Result (Nam) |
| and then Nkind (Parent (N)) = N_Object_Declaration |
| then |
| -- Verify that none of the formals are controlling |
| |
| declare |
| Call_OK : Boolean := False; |
| F : Entity_Id; |
| |
| begin |
| F := First_Formal (Nam); |
| while Present (F) loop |
| if Is_Controlling_Formal (F) then |
| Call_OK := True; |
| exit; |
| end if; |
| |
| Next_Formal (F); |
| end loop; |
| |
| if not Call_OK then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_N ("!cannot determine tag of result<<", N); |
| Error_Msg_N ("\Program_Error [<<!", N); |
| Insert_Action (N, |
| Make_Raise_Program_Error (Sloc (N), |
| Reason => PE_Explicit_Raise)); |
| end if; |
| end; |
| end if; |
| |
| -- Check the dimensions of the actuals in the call. For function calls, |
| -- propagate the dimensions from the returned type to N. |
| |
| Analyze_Dimension_Call (N, Nam); |
| |
| -- All done, evaluate call and deal with elaboration issues |
| |
| Eval_Call (N); |
| Check_Elab_Call (N); |
| Warn_On_Overlapping_Actuals (Nam, N); |
| end Resolve_Call; |
| |
| ----------------------------- |
| -- Resolve_Case_Expression -- |
| ----------------------------- |
| |
| procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is |
| Alt : Node_Id; |
| |
| begin |
| Alt := First (Alternatives (N)); |
| while Present (Alt) loop |
| Resolve (Expression (Alt), Typ); |
| Next (Alt); |
| end loop; |
| |
| Set_Etype (N, Typ); |
| Eval_Case_Expression (N); |
| end Resolve_Case_Expression; |
| |
| ------------------------------- |
| -- Resolve_Character_Literal -- |
| ------------------------------- |
| |
| procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| C : Entity_Id; |
| |
| begin |
| -- Verify that the character does belong to the type of the context |
| |
| Set_Etype (N, B_Typ); |
| Eval_Character_Literal (N); |
| |
| -- Wide_Wide_Character literals must always be defined, since the set |
| -- of wide wide character literals is complete, i.e. if a character |
| -- literal is accepted by the parser, then it is OK for wide wide |
| -- character (out of range character literals are rejected). |
| |
| if Root_Type (B_Typ) = Standard_Wide_Wide_Character then |
| return; |
| |
| -- Always accept character literal for type Any_Character, which |
| -- occurs in error situations and in comparisons of literals, both |
| -- of which should accept all literals. |
| |
| elsif B_Typ = Any_Character then |
| return; |
| |
| -- For Standard.Character or a type derived from it, check that the |
| -- literal is in range. |
| |
| elsif Root_Type (B_Typ) = Standard_Character then |
| if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then |
| return; |
| end if; |
| |
| -- For Standard.Wide_Character or a type derived from it, check that the |
| -- literal is in range. |
| |
| elsif Root_Type (B_Typ) = Standard_Wide_Character then |
| if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then |
| return; |
| end if; |
| |
| -- For Standard.Wide_Wide_Character or a type derived from it, we |
| -- know the literal is in range, since the parser checked. |
| |
| elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then |
| return; |
| |
| -- If the entity is already set, this has already been resolved in a |
| -- generic context, or comes from expansion. Nothing else to do. |
| |
| elsif Present (Entity (N)) then |
| return; |
| |
| -- Otherwise we have a user defined character type, and we can use the |
| -- standard visibility mechanisms to locate the referenced entity. |
| |
| else |
| C := Current_Entity (N); |
| while Present (C) loop |
| if Etype (C) = B_Typ then |
| Set_Entity_With_Checks (N, C); |
| Generate_Reference (C, N); |
| return; |
| end if; |
| |
| C := Homonym (C); |
| end loop; |
| end if; |
| |
| -- If we fall through, then the literal does not match any of the |
| -- entries of the enumeration type. This isn't just a constraint error |
| -- situation, it is an illegality (see RM 4.2). |
| |
| Error_Msg_NE |
| ("character not defined for }", N, First_Subtype (B_Typ)); |
| end Resolve_Character_Literal; |
| |
| --------------------------- |
| -- Resolve_Comparison_Op -- |
| --------------------------- |
| |
| -- Context requires a boolean type, and plays no role in resolution. |
| -- Processing identical to that for equality operators. The result type is |
| -- the base type, which matters when pathological subtypes of booleans with |
| -- limited ranges are used. |
| |
| procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| T : Entity_Id; |
| |
| begin |
| -- If this is an intrinsic operation which is not predefined, use the |
| -- types of its declared arguments to resolve the possibly overloaded |
| -- operands. Otherwise the operands are unambiguous and specify the |
| -- expected type. |
| |
| if Scope (Entity (N)) /= Standard_Standard then |
| T := Etype (First_Entity (Entity (N))); |
| |
| else |
| T := Find_Unique_Type (L, R); |
| |
| if T = Any_Fixed then |
| T := Unique_Fixed_Point_Type (L); |
| end if; |
| end if; |
| |
| Set_Etype (N, Base_Type (Typ)); |
| Generate_Reference (T, N, ' '); |
| |
| -- Skip remaining processing if already set to Any_Type |
| |
| if T = Any_Type then |
| return; |
| end if; |
| |
| -- Deal with other error cases |
| |
| if T = Any_String or else |
| T = Any_Composite or else |
| T = Any_Character |
| then |
| if T = Any_Character then |
| Ambiguous_Character (L); |
| else |
| Error_Msg_N ("ambiguous operands for comparison", N); |
| end if; |
| |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| -- Resolve the operands if types OK |
| |
| Resolve (L, T); |
| Resolve (R, T); |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (R); |
| Generate_Operator_Reference (N, T); |
| Check_Low_Bound_Tested (N); |
| |
| -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean |
| -- types or array types except String. |
| |
| if Is_Boolean_Type (T) then |
| Check_SPARK_Restriction |
| ("comparison is not defined on Boolean type", N); |
| |
| elsif Is_Array_Type (T) |
| and then Base_Type (T) /= Standard_String |
| then |
| Check_SPARK_Restriction |
| ("comparison is not defined on array types other than String", N); |
| end if; |
| |
| -- Check comparison on unordered enumeration |
| |
| if Bad_Unordered_Enumeration_Reference (N, Etype (L)) then |
| Error_Msg_Sloc := Sloc (Etype (L)); |
| Error_Msg_NE |
| ("comparison on unordered enumeration type& declared#?U?", |
| N, Etype (L)); |
| end if; |
| |
| -- Evaluate the relation (note we do this after the above check since |
| -- this Eval call may change N to True/False. |
| |
| Analyze_Dimension (N); |
| Eval_Relational_Op (N); |
| end Resolve_Comparison_Op; |
| |
| ----------------------------------------- |
| -- Resolve_Discrete_Subtype_Indication -- |
| ----------------------------------------- |
| |
| procedure Resolve_Discrete_Subtype_Indication |
| (N : Node_Id; |
| Typ : Entity_Id) |
| is |
| R : Node_Id; |
| S : Entity_Id; |
| |
| begin |
| Analyze (Subtype_Mark (N)); |
| S := Entity (Subtype_Mark (N)); |
| |
| if Nkind (Constraint (N)) /= N_Range_Constraint then |
| Error_Msg_N ("expect range constraint for discrete type", N); |
| Set_Etype (N, Any_Type); |
| |
| else |
| R := Range_Expression (Constraint (N)); |
| |
| if R = Error then |
| return; |
| end if; |
| |
| Analyze (R); |
| |
| if Base_Type (S) /= Base_Type (Typ) then |
| Error_Msg_NE |
| ("expect subtype of }", N, First_Subtype (Typ)); |
| |
| -- Rewrite the constraint as a range of Typ |
| -- to allow compilation to proceed further. |
| |
| Set_Etype (N, Typ); |
| Rewrite (Low_Bound (R), |
| Make_Attribute_Reference (Sloc (Low_Bound (R)), |
| Prefix => New_Occurrence_Of (Typ, Sloc (R)), |
| Attribute_Name => Name_First)); |
| Rewrite (High_Bound (R), |
| Make_Attribute_Reference (Sloc (High_Bound (R)), |
| Prefix => New_Occurrence_Of (Typ, Sloc (R)), |
| Attribute_Name => Name_First)); |
| |
| else |
| Resolve (R, Typ); |
| Set_Etype (N, Etype (R)); |
| |
| -- Additionally, we must check that the bounds are compatible |
| -- with the given subtype, which might be different from the |
| -- type of the context. |
| |
| Apply_Range_Check (R, S); |
| |
| -- ??? If the above check statically detects a Constraint_Error |
| -- it replaces the offending bound(s) of the range R with a |
| -- Constraint_Error node. When the itype which uses these bounds |
| -- is frozen the resulting call to Duplicate_Subexpr generates |
| -- a new temporary for the bounds. |
| |
| -- Unfortunately there are other itypes that are also made depend |
| -- on these bounds, so when Duplicate_Subexpr is called they get |
| -- a forward reference to the newly created temporaries and Gigi |
| -- aborts on such forward references. This is probably sign of a |
| -- more fundamental problem somewhere else in either the order of |
| -- itype freezing or the way certain itypes are constructed. |
| |
| -- To get around this problem we call Remove_Side_Effects right |
| -- away if either bounds of R are a Constraint_Error. |
| |
| declare |
| L : constant Node_Id := Low_Bound (R); |
| H : constant Node_Id := High_Bound (R); |
| |
| begin |
| if Nkind (L) = N_Raise_Constraint_Error then |
| Remove_Side_Effects (L); |
| end if; |
| |
| if Nkind (H) = N_Raise_Constraint_Error then |
| Remove_Side_Effects (H); |
| end if; |
| end; |
| |
| Check_Unset_Reference (Low_Bound (R)); |
| Check_Unset_Reference (High_Bound (R)); |
| end if; |
| end if; |
| end Resolve_Discrete_Subtype_Indication; |
| |
| ------------------------- |
| -- Resolve_Entity_Name -- |
| ------------------------- |
| |
| -- Used to resolve identifiers and expanded names |
| |
| procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is |
| function Appears_In_Check (Nod : Node_Id) return Boolean; |
| -- Denote whether an arbitrary node Nod appears in a check node |
| |
| ---------------------- |
| -- Appears_In_Check -- |
| ---------------------- |
| |
| function Appears_In_Check (Nod : Node_Id) return Boolean is |
| Par : Node_Id; |
| |
| begin |
| -- Climb the parent chain looking for a check node |
| |
| Par := Nod; |
| while Present (Par) loop |
| if Nkind (Par) in N_Raise_xxx_Error then |
| return True; |
| |
| -- Prevent the search from going too far |
| |
| elsif Is_Body_Or_Package_Declaration (Par) then |
| exit; |
| end if; |
| |
| Par := Parent (Par); |
| end loop; |
| |
| return False; |
| end Appears_In_Check; |
| |
| -- Local variables |
| |
| E : constant Entity_Id := Entity (N); |
| Par : constant Node_Id := Parent (N); |
| |
| -- Start of processing for Resolve_Entity_Name |
| |
| begin |
| -- If garbage from errors, set to Any_Type and return |
| |
| if No (E) and then Total_Errors_Detected /= 0 then |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| -- Replace named numbers by corresponding literals. Note that this is |
| -- the one case where Resolve_Entity_Name must reset the Etype, since |
| -- it is currently marked as universal. |
| |
| if Ekind (E) = E_Named_Integer then |
| Set_Etype (N, Typ); |
| Eval_Named_Integer (N); |
| |
| elsif Ekind (E) = E_Named_Real then |
| Set_Etype (N, Typ); |
| Eval_Named_Real (N); |
| |
| -- For enumeration literals, we need to make sure that a proper style |
| -- check is done, since such literals are overloaded, and thus we did |
| -- not do a style check during the first phase of analysis. |
| |
| elsif Ekind (E) = E_Enumeration_Literal then |
| Set_Entity_With_Checks (N, E); |
| Eval_Entity_Name (N); |
| |
| -- Case of subtype name appearing as an operand in expression |
| |
| elsif Is_Type (E) then |
| |
| -- Allow use of subtype if it is a concurrent type where we are |
| -- currently inside the body. This will eventually be expanded into a |
| -- call to Self (for tasks) or _object (for protected objects). Any |
| -- other use of a subtype is invalid. |
| |
| if Is_Concurrent_Type (E) |
| and then In_Open_Scopes (E) |
| then |
| null; |
| |
| -- Any other use is an error |
| |
| else |
| Error_Msg_N |
| ("invalid use of subtype mark in expression or call", N); |
| end if; |
| |
| -- Check discriminant use if entity is discriminant in current scope, |
| -- i.e. discriminant of record or concurrent type currently being |
| -- analyzed. Uses in corresponding body are unrestricted. |
| |
| elsif Ekind (E) = E_Discriminant |
| and then Scope (E) = Current_Scope |
| and then not Has_Completion (Current_Scope) |
| then |
| Check_Discriminant_Use (N); |
| |
| -- A parameterless generic function cannot appear in a context that |
| -- requires resolution. |
| |
| elsif Ekind (E) = E_Generic_Function then |
| Error_Msg_N ("illegal use of generic function", N); |
| |
| elsif Ekind (E) = E_Out_Parameter |
| and then Ada_Version = Ada_83 |
| and then (Nkind (Parent (N)) in N_Op |
| or else (Nkind (Parent (N)) = N_Assignment_Statement |
| and then N = Expression (Parent (N))) |
| or else Nkind (Parent (N)) = N_Explicit_Dereference) |
| then |
| Error_Msg_N ("(Ada 83) illegal reading of out parameter", N); |
| |
| -- In all other cases, just do the possible static evaluation |
| |
| else |
| -- A deferred constant that appears in an expression must have a |
| -- completion, unless it has been removed by in-place expansion of |
| -- an aggregate. |
| |
| if Ekind (E) = E_Constant |
| and then Comes_From_Source (E) |
| and then No (Constant_Value (E)) |
| and then Is_Frozen (Etype (E)) |
| and then not In_Spec_Expression |
| and then not Is_Imported (E) |
| then |
| if No_Initialization (Parent (E)) |
| or else (Present (Full_View (E)) |
| and then No_Initialization (Parent (Full_View (E)))) |
| then |
| null; |
| else |
| Error_Msg_N ( |
| "deferred constant is frozen before completion", N); |
| end if; |
| end if; |
| |
| Eval_Entity_Name (N); |
| end if; |
| |
| -- A volatile object subject to enabled properties Async_Writers or |
| -- Effective_Reads must appear in a specific context. The following |
| -- checks are only relevant when SPARK_Mode is on as they are not |
| -- standard Ada legality rules. |
| |
| if SPARK_Mode = On |
| and then Ekind_In (E, E_Abstract_State, E_Variable) |
| and then Is_SPARK_Volatile_Object (E) |
| and then |
| (Async_Writers_Enabled (E) |
| or else Effective_Reads_Enabled (E)) |
| then |
| -- The volatile object can appear on either side of an assignment |
| |
| if Nkind (Par) = N_Assignment_Statement then |
| null; |
| |
| -- The volatile object is part of the initialization expression of |
| -- another object. Ensure that the climb of the parent chain came |
| -- from the expression side and not from the name side. |
| |
| elsif Nkind (Par) = N_Object_Declaration |
| and then Present (Expression (Par)) |
| and then N = Expression (Par) |
| then |
| null; |
| |
| -- The volatile object appears as an actual parameter in a call to an |
| -- instance of Unchecked_Conversion whose result is renamed. |
| |
| elsif Nkind (Par) = N_Function_Call |
| and then Is_Unchecked_Conversion_Instance (Entity (Name (Par))) |
| and then Nkind (Parent (Par)) = N_Object_Renaming_Declaration |
| then |
| null; |
| |
| -- Assume that references to volatile objects that appear as actual |
| -- parameters in a procedure call are always legal. The full legality |
| -- check is done when the actuals are resolved. |
| |
| elsif Nkind (Par) = N_Procedure_Call_Statement then |
| null; |
| |
| -- Allow references to volatile objects in various checks |
| |
| elsif Appears_In_Check (Par) then |
| null; |
| |
| else |
| Error_Msg_N |
| ("volatile object cannot appear in this context " |
| & "(SPARK RM 7.1.3(13))", N); |
| end if; |
| end if; |
| end Resolve_Entity_Name; |
| |
| ------------------- |
| -- Resolve_Entry -- |
| ------------------- |
| |
| procedure Resolve_Entry (Entry_Name : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (Entry_Name); |
| Nam : Entity_Id; |
| New_N : Node_Id; |
| S : Entity_Id; |
| Tsk : Entity_Id; |
| E_Name : Node_Id; |
| Index : Node_Id; |
| |
| function Actual_Index_Type (E : Entity_Id) return Entity_Id; |
| -- If the bounds of the entry family being called depend on task |
| -- discriminants, build a new index subtype where a discriminant is |
| -- replaced with the value of the discriminant of the target task. |
| -- The target task is the prefix of the entry name in the call. |
| |
| ----------------------- |
| -- Actual_Index_Type -- |
| ----------------------- |
| |
| function Actual_Index_Type (E : Entity_Id) return Entity_Id is |
| Typ : constant Entity_Id := Entry_Index_Type (E); |
| Tsk : constant Entity_Id := Scope (E); |
| Lo : constant Node_Id := Type_Low_Bound (Typ); |
| Hi : constant Node_Id := Type_High_Bound (Typ); |
| New_T : Entity_Id; |
| |
| function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id; |
| -- If the bound is given by a discriminant, replace with a reference |
| -- to the discriminant of the same name in the target task. If the |
| -- entry name is the target of a requeue statement and the entry is |
| -- in the current protected object, the bound to be used is the |
| -- discriminal of the object (see Apply_Range_Checks for details of |
| -- the transformation). |
| |
| ----------------------------- |
| -- Actual_Discriminant_Ref -- |
| ----------------------------- |
| |
| function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is |
| Typ : constant Entity_Id := Etype (Bound); |
| Ref : Node_Id; |
| |
| begin |
| Remove_Side_Effects (Bound); |
| |
| if not Is_Entity_Name (Bound) |
| or else Ekind (Entity (Bound)) /= E_Discriminant |
| then |
| return Bound; |
| |
| elsif Is_Protected_Type (Tsk) |
| and then In_Open_Scopes (Tsk) |
| and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement |
| then |
| -- Note: here Bound denotes a discriminant of the corresponding |
| -- record type tskV, whose discriminal is a formal of the |
| -- init-proc tskVIP. What we want is the body discriminal, |
| -- which is associated to the discriminant of the original |
| -- concurrent type tsk. |
| |
| return New_Occurrence_Of |
| (Find_Body_Discriminal (Entity (Bound)), Loc); |
| |
| else |
| Ref := |
| Make_Selected_Component (Loc, |
| Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))), |
| Selector_Name => New_Occurrence_Of (Entity (Bound), Loc)); |
| Analyze (Ref); |
| Resolve (Ref, Typ); |
| return Ref; |
| end if; |
| end Actual_Discriminant_Ref; |
| |
| -- Start of processing for Actual_Index_Type |
| |
| begin |
| if not Has_Discriminants (Tsk) |
| or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi)) |
| then |
| return Entry_Index_Type (E); |
| |
| else |
| New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name)); |
| Set_Etype (New_T, Base_Type (Typ)); |
| Set_Size_Info (New_T, Typ); |
| Set_RM_Size (New_T, RM_Size (Typ)); |
| Set_Scalar_Range (New_T, |
| Make_Range (Sloc (Entry_Name), |
| Low_Bound => Actual_Discriminant_Ref (Lo), |
| High_Bound => Actual_Discriminant_Ref (Hi))); |
| |
| return New_T; |
| end if; |
| end Actual_Index_Type; |
| |
| -- Start of processing of Resolve_Entry |
| |
| begin |
| -- Find name of entry being called, and resolve prefix of name with its |
| -- own type. The prefix can be overloaded, and the name and signature of |
| -- the entry must be taken into account. |
| |
| if Nkind (Entry_Name) = N_Indexed_Component then |
| |
| -- Case of dealing with entry family within the current tasks |
| |
| E_Name := Prefix (Entry_Name); |
| |
| else |
| E_Name := Entry_Name; |
| end if; |
| |
| if Is_Entity_Name (E_Name) then |
| |
| -- Entry call to an entry (or entry family) in the current task. This |
| -- is legal even though the task will deadlock. Rewrite as call to |
| -- current task. |
| |
| -- This can also be a call to an entry in an enclosing task. If this |
| -- is a single task, we have to retrieve its name, because the scope |
| -- of the entry is the task type, not the object. If the enclosing |
| -- task is a task type, the identity of the task is given by its own |
| -- self variable. |
| |
| -- Finally this can be a requeue on an entry of the same task or |
| -- protected object. |
| |
| S := Scope (Entity (E_Name)); |
| |
| for J in reverse 0 .. Scope_Stack.Last loop |
| if Is_Task_Type (Scope_Stack.Table (J).Entity) |
| and then not Comes_From_Source (S) |
| then |
| -- S is an enclosing task or protected object. The concurrent |
| -- declaration has been converted into a type declaration, and |
| -- the object itself has an object declaration that follows |
| -- the type in the same declarative part. |
| |
| Tsk := Next_Entity (S); |
| while Etype (Tsk) /= S loop |
| Next_Entity (Tsk); |
| end loop; |
| |
| S := Tsk; |
| exit; |
| |
| elsif S = Scope_Stack.Table (J).Entity then |
| |
| -- Call to current task. Will be transformed into call to Self |
| |
| exit; |
| |
| end if; |
| end loop; |
| |
| New_N := |
| Make_Selected_Component (Loc, |
| Prefix => New_Occurrence_Of (S, Loc), |
| Selector_Name => |
| New_Occurrence_Of (Entity (E_Name), Loc)); |
| Rewrite (E_Name, New_N); |
| Analyze (E_Name); |
| |
| elsif Nkind (Entry_Name) = N_Selected_Component |
| and then Is_Overloaded (Prefix (Entry_Name)) |
| then |
| -- Use the entry name (which must be unique at this point) to find |
| -- the prefix that returns the corresponding task/protected type. |
| |
| declare |
| Pref : constant Node_Id := Prefix (Entry_Name); |
| Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name)); |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (Pref, I, It); |
| while Present (It.Typ) loop |
| if Scope (Ent) = It.Typ then |
| Set_Etype (Pref, It.Typ); |
| exit; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end; |
| end if; |
| |
| if Nkind (Entry_Name) = N_Selected_Component then |
| Resolve (Prefix (Entry_Name)); |
| |
| else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component); |
| Nam := Entity (Selector_Name (Prefix (Entry_Name))); |
| Resolve (Prefix (Prefix (Entry_Name))); |
| Index := First (Expressions (Entry_Name)); |
| Resolve (Index, Entry_Index_Type (Nam)); |
| |
| -- Up to this point the expression could have been the actual in a |
| -- simple entry call, and be given by a named association. |
| |
| if Nkind (Index) = N_Parameter_Association then |
| Error_Msg_N ("expect expression for entry index", Index); |
| else |
| Apply_Range_Check (Index, Actual_Index_Type (Nam)); |
| end if; |
| end if; |
| end Resolve_Entry; |
| |
| ------------------------ |
| -- Resolve_Entry_Call -- |
| ------------------------ |
| |
| procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is |
| Entry_Name : constant Node_Id := Name (N); |
| Loc : constant Source_Ptr := Sloc (Entry_Name); |
| Actuals : List_Id; |
| First_Named : Node_Id; |
| Nam : Entity_Id; |
| Norm_OK : Boolean; |
| Obj : Node_Id; |
| Was_Over : Boolean; |
| |
| begin |
| -- We kill all checks here, because it does not seem worth the effort to |
| -- do anything better, an entry call is a big operation. |
| |
| Kill_All_Checks; |
| |
| -- Processing of the name is similar for entry calls and protected |
| -- operation calls. Once the entity is determined, we can complete |
| -- the resolution of the actuals. |
| |
| -- The selector may be overloaded, in the case of a protected object |
| -- with overloaded functions. The type of the context is used for |
| -- resolution. |
| |
| if Nkind (Entry_Name) = N_Selected_Component |
| and then Is_Overloaded (Selector_Name (Entry_Name)) |
| and then Typ /= Standard_Void_Type |
| then |
| declare |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (Selector_Name (Entry_Name), I, It); |
| while Present (It.Typ) loop |
| if Covers (Typ, It.Typ) then |
| Set_Entity (Selector_Name (Entry_Name), It.Nam); |
| Set_Etype (Entry_Name, It.Typ); |
| |
| Generate_Reference (It.Typ, N, ' '); |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end; |
| end if; |
| |
| Resolve_Entry (Entry_Name); |
| |
| if Nkind (Entry_Name) = N_Selected_Component then |
| |
| -- Simple entry call |
| |
| Nam := Entity (Selector_Name (Entry_Name)); |
| Obj := Prefix (Entry_Name); |
| Was_Over := Is_Overloaded (Selector_Name (Entry_Name)); |
| |
| else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component); |
| |
| -- Call to member of entry family |
| |
| Nam := Entity (Selector_Name (Prefix (Entry_Name))); |
| Obj := Prefix (Prefix (Entry_Name)); |
| Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name))); |
| end if; |
| |
| -- We cannot in general check the maximum depth of protected entry calls |
| -- at compile time. But we can tell that any protected entry call at all |
| -- violates a specified nesting depth of zero. |
| |
| if Is_Protected_Type (Scope (Nam)) then |
| Check_Restriction (Max_Entry_Queue_Length, N); |
| end if; |
| |
| -- Use context type to disambiguate a protected function that can be |
| -- called without actuals and that returns an array type, and where the |
| -- argument list may be an indexing of the returned value. |
| |
| if Ekind (Nam) = E_Function |
| and then Needs_No_Actuals (Nam) |
| and then Present (Parameter_Associations (N)) |
| and then |
| ((Is_Array_Type (Etype (Nam)) |
| and then Covers (Typ, Component_Type (Etype (Nam)))) |
| |
| or else (Is_Access_Type (Etype (Nam)) |
| and then Is_Array_Type (Designated_Type (Etype (Nam))) |
| and then |
| Covers |
| (Typ, |
| Component_Type (Designated_Type (Etype (Nam)))))) |
| then |
| declare |
| Index_Node : Node_Id; |
| |
| begin |
| Index_Node := |
| Make_Indexed_Component (Loc, |
| Prefix => |
| Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)), |
| Expressions => Parameter_Associations (N)); |
| |
| -- Since we are correcting a node classification error made by the |
| -- parser, we call Replace rather than Rewrite. |
| |
| Replace (N, Index_Node); |
| Set_Etype (Prefix (N), Etype (Nam)); |
| Set_Etype (N, Typ); |
| Resolve_Indexed_Component (N, Typ); |
| return; |
| end; |
| end if; |
| |
| if Ekind_In (Nam, E_Entry, E_Entry_Family) |
| and then Present (PPC_Wrapper (Nam)) |
| and then Current_Scope /= PPC_Wrapper (Nam) |
| then |
| -- Rewrite as call to the precondition wrapper, adding the task |
| -- object to the list of actuals. If the call is to a member of an |
| -- entry family, include the index as well. |
| |
| declare |
| New_Call : Node_Id; |
| New_Actuals : List_Id; |
| |
| begin |
| New_Actuals := New_List (Obj); |
| |
| if Nkind (Entry_Name) = N_Indexed_Component then |
| Append_To (New_Actuals, |
| New_Copy_Tree (First (Expressions (Entry_Name)))); |
| end if; |
| |
| Append_List (Parameter_Associations (N), New_Actuals); |
| New_Call := |
| Make_Procedure_Call_Statement (Loc, |
| Name => |
| New_Occurrence_Of (PPC_Wrapper (Nam), Loc), |
| Parameter_Associations => New_Actuals); |
| Rewrite (N, New_Call); |
| Analyze_And_Resolve (N); |
| return; |
| end; |
| end if; |
| |
| -- The operation name may have been overloaded. Order the actuals |
| -- according to the formals of the resolved entity, and set the return |
| -- type to that of the operation. |
| |
| if Was_Over then |
| Normalize_Actuals (N, Nam, False, Norm_OK); |
| pragma Assert (Norm_OK); |
| Set_Etype (N, Etype (Nam)); |
| end if; |
| |
| Resolve_Actuals (N, Nam); |
| Check_Internal_Protected_Use (N, Nam); |
| |
| -- Create a call reference to the entry |
| |
| Generate_Reference (Nam, Entry_Name, 's'); |
| |
| if Ekind_In (Nam, E_Entry, E_Entry_Family) then |
| Check_Potentially_Blocking_Operation (N); |
| end if; |
| |
| -- Verify that a procedure call cannot masquerade as an entry |
| -- call where an entry call is expected. |
| |
| if Ekind (Nam) = E_Procedure then |
| if Nkind (Parent (N)) = N_Entry_Call_Alternative |
| and then N = Entry_Call_Statement (Parent (N)) |
| then |
| Error_Msg_N ("entry call required in select statement", N); |
| |
| elsif Nkind (Parent (N)) = N_Triggering_Alternative |
| and then N = Triggering_Statement (Parent (N)) |
| then |
| Error_Msg_N ("triggering statement cannot be procedure call", N); |
| |
| elsif Ekind (Scope (Nam)) = E_Task_Type |
| and then not In_Open_Scopes (Scope (Nam)) |
| then |
| Error_Msg_N ("task has no entry with this name", Entry_Name); |
| end if; |
| end if; |
| |
| -- After resolution, entry calls and protected procedure calls are |
| -- changed into entry calls, for expansion. The structure of the node |
| -- does not change, so it can safely be done in place. Protected |
| -- function calls must keep their structure because they are |
| -- subexpressions. |
| |
| if Ekind (Nam) /= E_Function then |
| |
| -- A protected operation that is not a function may modify the |
| -- corresponding object, and cannot apply to a constant. If this |
| -- is an internal call, the prefix is the type itself. |
| |
| if Is_Protected_Type (Scope (Nam)) |
| and then not Is_Variable (Obj) |
| and then (not Is_Entity_Name (Obj) |
| or else not Is_Type (Entity (Obj))) |
| then |
| Error_Msg_N |
| ("prefix of protected procedure or entry call must be variable", |
| Entry_Name); |
| end if; |
| |
| Actuals := Parameter_Associations (N); |
| First_Named := First_Named_Actual (N); |
| |
| Rewrite (N, |
| Make_Entry_Call_Statement (Loc, |
| Name => Entry_Name, |
| Parameter_Associations => Actuals)); |
| |
| Set_First_Named_Actual (N, First_Named); |
| Set_Analyzed (N, True); |
| |
| -- Protected functions can return on the secondary stack, in which |
| -- case we must trigger the transient scope mechanism. |
| |
| elsif Expander_Active |
| and then Requires_Transient_Scope (Etype (Nam)) |
| then |
| Establish_Transient_Scope (N, Sec_Stack => True); |
| end if; |
| end Resolve_Entry_Call; |
| |
| ------------------------- |
| -- Resolve_Equality_Op -- |
| ------------------------- |
| |
| -- Both arguments must have the same type, and the boolean context does |
| -- not participate in the resolution. The first pass verifies that the |
| -- interpretation is not ambiguous, and the type of the left argument is |
| -- correctly set, or is Any_Type in case of ambiguity. If both arguments |
| -- are strings or aggregates, allocators, or Null, they are ambiguous even |
| -- though they carry a single (universal) type. Diagnose this case here. |
| |
| procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| T : Entity_Id := Find_Unique_Type (L, R); |
| |
| procedure Check_If_Expression (Cond : Node_Id); |
| -- The resolution rule for if expressions requires that each such must |
| -- have a unique type. This means that if several dependent expressions |
| -- are of a non-null anonymous access type, and the context does not |
| -- impose an expected type (as can be the case in an equality operation) |
| -- the expression must be rejected. |
| |
| procedure Explain_Redundancy (N : Node_Id); |
| -- Attempt to explain the nature of a redundant comparison with True. If |
| -- the expression N is too complex, this routine issues a general error |
| -- message. |
| |
| function Find_Unique_Access_Type return Entity_Id; |
| -- In the case of allocators and access attributes, the context must |
| -- provide an indication of the specific access type to be used. If |
| -- one operand is of such a "generic" access type, check whether there |
| -- is a specific visible access type that has the same designated type. |
| -- This is semantically dubious, and of no interest to any real code, |
| -- but c48008a makes it all worthwhile. |
| |
| ------------------------- |
| -- Check_If_Expression -- |
| ------------------------- |
| |
| procedure Check_If_Expression (Cond : Node_Id) is |
| Then_Expr : Node_Id; |
| Else_Expr : Node_Id; |
| |
| begin |
| if Nkind (Cond) = N_If_Expression then |
| Then_Expr := Next (First (Expressions (Cond))); |
| Else_Expr := Next (Then_Expr); |
| |
| if Nkind (Then_Expr) /= N_Null |
| and then Nkind (Else_Expr) /= N_Null |
| then |
| Error_Msg_N ("cannot determine type of if expression", Cond); |
| end if; |
| end if; |
| end Check_If_Expression; |
| |
| ------------------------ |
| -- Explain_Redundancy -- |
| ------------------------ |
| |
| procedure Explain_Redundancy (N : Node_Id) is |
| Error : Name_Id; |
| Val : Node_Id; |
| Val_Id : Entity_Id; |
| |
| begin |
| Val := N; |
| |
| -- Strip the operand down to an entity |
| |
| loop |
| if Nkind (Val) = N_Selected_Component then |
| Val := Selector_Name (Val); |
| else |
| exit; |
| end if; |
| end loop; |
| |
| -- The construct denotes an entity |
| |
| if Is_Entity_Name (Val) and then Present (Entity (Val)) then |
| Val_Id := Entity (Val); |
| |
| -- Do not generate an error message when the comparison is done |
| -- against the enumeration literal Standard.True. |
| |
| if Ekind (Val_Id) /= E_Enumeration_Literal then |
| |
| -- Build a customized error message |
| |
| Name_Len := 0; |
| Add_Str_To_Name_Buffer ("?r?"); |
| |
| if Ekind (Val_Id) = E_Component then |
| Add_Str_To_Name_Buffer ("component "); |
| |
| elsif Ekind (Val_Id) = E_Constant then |
| Add_Str_To_Name_Buffer ("constant "); |
| |
| elsif Ekind (Val_Id) = E_Discriminant then |
| Add_Str_To_Name_Buffer ("discriminant "); |
| |
| elsif Is_Formal (Val_Id) then |
| Add_Str_To_Name_Buffer ("parameter "); |
| |
| elsif Ekind (Val_Id) = E_Variable then |
| Add_Str_To_Name_Buffer ("variable "); |
| end if; |
| |
| Add_Str_To_Name_Buffer ("& is always True!"); |
| Error := Name_Find; |
| |
| Error_Msg_NE (Get_Name_String (Error), Val, Val_Id); |
| end if; |
| |
| -- The construct is too complex to disect, issue a general message |
| |
| else |
| Error_Msg_N ("?r?expression is always True!", Val); |
| end if; |
| end Explain_Redundancy; |
| |
| ----------------------------- |
| -- Find_Unique_Access_Type -- |
| ----------------------------- |
| |
| function Find_Unique_Access_Type return Entity_Id is |
| Acc : Entity_Id; |
| E : Entity_Id; |
| S : Entity_Id; |
| |
| begin |
| if Ekind_In (Etype (R), E_Allocator_Type, |
| E_Access_Attribute_Type) |
| then |
| Acc := Designated_Type (Etype (R)); |
| |
| elsif Ekind_In (Etype (L), E_Allocator_Type, |
| E_Access_Attribute_Type) |
| then |
| Acc := Designated_Type (Etype (L)); |
| else |
| return Empty; |
| end if; |
| |
| S := Current_Scope; |
| while S /= Standard_Standard loop |
| E := First_Entity (S); |
| while Present (E) loop |
| if Is_Type (E) |
| and then Is_Access_Type (E) |
| and then Ekind (E) /= E_Allocator_Type |
| and then Designated_Type (E) = Base_Type (Acc) |
| then |
| return E; |
| end if; |
| |
| Next_Entity (E); |
| end loop; |
| |
| S := Scope (S); |
| end loop; |
| |
| return Empty; |
| end Find_Unique_Access_Type; |
| |
| -- Start of processing for Resolve_Equality_Op |
| |
| begin |
| Set_Etype (N, Base_Type (Typ)); |
| Generate_Reference (T, N, ' '); |
| |
| if T = Any_Fixed then |
| T := Unique_Fixed_Point_Type (L); |
| end if; |
| |
| if T /= Any_Type then |
| if T = Any_String or else |
| T = Any_Composite or else |
| T = Any_Character |
| then |
| if T = Any_Character then |
| Ambiguous_Character (L); |
| else |
| Error_Msg_N ("ambiguous operands for equality", N); |
| end if; |
| |
| Set_Etype (N, Any_Type); |
| return; |
| |
| elsif T = Any_Access |
| or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type) |
| then |
| T := Find_Unique_Access_Type; |
| |
| if No (T) then |
| Error_Msg_N ("ambiguous operands for equality", N); |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| -- If expressions must have a single type, and if the context does |
| -- not impose one the dependent expressions cannot be anonymous |
| -- access types. |
| |
| -- Why no similar processing for case expressions??? |
| |
| elsif Ada_Version >= Ada_2012 |
| and then Ekind_In (Etype (L), E_Anonymous_Access_Type, |
| E_Anonymous_Access_Subprogram_Type) |
| and then Ekind_In (Etype (R), E_Anonymous_Access_Type, |
| E_Anonymous_Access_Subprogram_Type) |
| then |
| Check_If_Expression (L); |
| Check_If_Expression (R); |
| end if; |
| |
| Resolve (L, T); |
| Resolve (R, T); |
| |
| -- In SPARK, equality operators = and /= for array types other than |
| -- String are only defined when, for each index position, the |
| -- operands have equal static bounds. |
| |
| if Is_Array_Type (T) then |
| |
| -- Protect call to Matching_Static_Array_Bounds to avoid costly |
| -- operation if not needed. |
| |
| if Restriction_Check_Required (SPARK_05) |
| and then Base_Type (T) /= Standard_String |
| and then Base_Type (Etype (L)) = Base_Type (Etype (R)) |
| and then Etype (L) /= Any_Composite -- or else L in error |
| and then Etype (R) /= Any_Composite -- or else R in error |
| and then not Matching_Static_Array_Bounds (Etype (L), Etype (R)) |
| then |
| Check_SPARK_Restriction |
| ("array types should have matching static bounds", N); |
| end if; |
| end if; |
| |
| -- If the unique type is a class-wide type then it will be expanded |
| -- into a dispatching call to the predefined primitive. Therefore we |
| -- check here for potential violation of such restriction. |
| |
| if Is_Class_Wide_Type (T) then |
| Check_Restriction (No_Dispatching_Calls, N); |
| end if; |
| |
| if Warn_On_Redundant_Constructs |
| and then Comes_From_Source (N) |
| and then Comes_From_Source (R) |
| and then Is_Entity_Name (R) |
| and then Entity (R) = Standard_True |
| then |
| Error_Msg_N -- CODEFIX |
| ("?r?comparison with True is redundant!", N); |
| Explain_Redundancy (Original_Node (R)); |
| end if; |
| |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (R); |
| Generate_Operator_Reference (N, T); |
| Check_Low_Bound_Tested (N); |
| |
| -- If this is an inequality, it may be the implicit inequality |
| -- created for a user-defined operation, in which case the corres- |
| -- ponding equality operation is not intrinsic, and the operation |
| -- cannot be constant-folded. Else fold. |
| |
| if Nkind (N) = N_Op_Eq |
| or else Comes_From_Source (Entity (N)) |
| or else Ekind (Entity (N)) = E_Operator |
| or else Is_Intrinsic_Subprogram |
| (Corresponding_Equality (Entity (N))) |
| then |
| Analyze_Dimension (N); |
| Eval_Relational_Op (N); |
| |
| elsif Nkind (N) = N_Op_Ne |
| and then Is_Abstract_Subprogram (Entity (N)) |
| then |
| Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N)); |
| end if; |
| |
| -- Ada 2005: If one operand is an anonymous access type, convert the |
| -- other operand to it, to ensure that the underlying types match in |
| -- the back-end. Same for access_to_subprogram, and the conversion |
| -- verifies that the types are subtype conformant. |
| |
| -- We apply the same conversion in the case one of the operands is a |
| -- private subtype of the type of the other. |
| |
| -- Why the Expander_Active test here ??? |
| |
| if Expander_Active |
| and then |
| (Ekind_In (T, E_Anonymous_Access_Type, |
| E_Anonymous_Access_Subprogram_Type) |
| or else Is_Private_Type (T)) |
| then |
| if Etype (L) /= T then |
| Rewrite (L, |
| Make_Unchecked_Type_Conversion (Sloc (L), |
| Subtype_Mark => New_Occurrence_Of (T, Sloc (L)), |
| Expression => Relocate_Node (L))); |
| Analyze_And_Resolve (L, T); |
| end if; |
| |
| if (Etype (R)) /= T then |
| Rewrite (R, |
| Make_Unchecked_Type_Conversion (Sloc (R), |
| Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)), |
| Expression => Relocate_Node (R))); |
| Analyze_And_Resolve (R, T); |
| end if; |
| end if; |
| end if; |
| end Resolve_Equality_Op; |
| |
| ---------------------------------- |
| -- Resolve_Explicit_Dereference -- |
| ---------------------------------- |
| |
| procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| New_N : Node_Id; |
| P : constant Node_Id := Prefix (N); |
| |
| P_Typ : Entity_Id; |
| -- The candidate prefix type, if overloaded |
| |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| Check_Fully_Declared_Prefix (Typ, P); |
| P_Typ := Empty; |
| |
| -- A useful optimization: check whether the dereference denotes an |
| -- element of a container, and if so rewrite it as a call to the |
| -- corresponding Element function. |
| |
| -- Disabled for now, on advice of ARG. A more restricted form of the |
| -- predicate might be acceptable ??? |
| |
| -- if Is_Container_Element (N) then |
| -- return; |
| -- end if; |
| |
| if Is_Overloaded (P) then |
| |
| -- Use the context type to select the prefix that has the correct |
| -- designated type. Keep the first match, which will be the inner- |
| -- most. |
| |
| Get_First_Interp (P, I, It); |
| |
| while Present (It.Typ) loop |
| if Is_Access_Type (It.Typ) |
| and then Covers (Typ, Designated_Type (It.Typ)) |
| then |
| if No (P_Typ) then |
| P_Typ := It.Typ; |
| end if; |
| |
| -- Remove access types that do not match, but preserve access |
| -- to subprogram interpretations, in case a further dereference |
| -- is needed (see below). |
| |
| elsif Ekind (It.Typ) /= E_Access_Subprogram_Type then |
| Remove_Interp (I); |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| if Present (P_Typ) then |
| Resolve (P, P_Typ); |
| Set_Etype (N, Designated_Type (P_Typ)); |
| |
| else |
| -- If no interpretation covers the designated type of the prefix, |
| -- this is the pathological case where not all implementations of |
| -- the prefix allow the interpretation of the node as a call. Now |
| -- that the expected type is known, Remove other interpretations |
| -- from prefix, rewrite it as a call, and resolve again, so that |
| -- the proper call node is generated. |
| |
| Get_First_Interp (P, I, It); |
| while Present (It.Typ) loop |
| if Ekind (It.Typ) /= E_Access_Subprogram_Type then |
| Remove_Interp (I); |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| New_N := |
| Make_Function_Call (Loc, |
| Name => |
| Make_Explicit_Dereference (Loc, |
| Prefix => P), |
| Parameter_Associations => New_List); |
| |
| Save_Interps (N, New_N); |
| Rewrite (N, New_N); |
| Analyze_And_Resolve (N, Typ); |
| return; |
| end if; |
| |
| -- If not overloaded, resolve P with its own type |
| |
| else |
| Resolve (P); |
| end if; |
| |
| if Is_Access_Type (Etype (P)) then |
| Apply_Access_Check (N); |
| end if; |
| |
| -- If the designated type is a packed unconstrained array type, and the |
| -- explicit dereference is not in the context of an attribute reference, |
| -- then we must compute and set the actual subtype, since it is needed |
| -- by Gigi. The reason we exclude the attribute case is that this is |
| -- handled fine by Gigi, and in fact we use such attributes to build the |
| -- actual subtype. We also exclude generated code (which builds actual |
| -- subtypes directly if they are needed). |
| |
| if Is_Array_Type (Etype (N)) |
| and then Is_Packed (Etype (N)) |
| and then not Is_Constrained (Etype (N)) |
| and then Nkind (Parent (N)) /= N_Attribute_Reference |
| and then Comes_From_Source (N) |
| then |
| Set_Etype (N, Get_Actual_Subtype (N)); |
| end if; |
| |
| -- Note: No Eval processing is required for an explicit dereference, |
| -- because such a name can never be static. |
| |
| end Resolve_Explicit_Dereference; |
| |
| ------------------------------------- |
| -- Resolve_Expression_With_Actions -- |
| ------------------------------------- |
| |
| procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is |
| begin |
| Set_Etype (N, Typ); |
| |
| -- If N has no actions, and its expression has been constant folded, |
| -- then rewrite N as just its expression. Note, we can't do this in |
| -- the general case of Is_Empty_List (Actions (N)) as this would cause |
| -- Expression (N) to be expanded again. |
| |
| if Is_Empty_List (Actions (N)) |
| and then Compile_Time_Known_Value (Expression (N)) |
| then |
| Rewrite (N, Expression (N)); |
| end if; |
| end Resolve_Expression_With_Actions; |
| |
| ---------------------------------- |
| -- Resolve_Generalized_Indexing -- |
| ---------------------------------- |
| |
| procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id) is |
| Indexing : constant Node_Id := Generalized_Indexing (N); |
| Call : Node_Id; |
| Indices : List_Id; |
| Pref : Node_Id; |
| |
| begin |
| -- In ASIS mode, propagate the information about the indices back to |
| -- to the original indexing node. The generalized indexing is either |
| -- a function call, or a dereference of one. The actuals include the |
| -- prefix of the original node, which is the container expression. |
| |
| if ASIS_Mode then |
| Resolve (Indexing, Typ); |
| Set_Etype (N, Etype (Indexing)); |
| Set_Is_Overloaded (N, False); |
| |
| Call := Indexing; |
| while Nkind_In (Call, N_Explicit_Dereference, N_Selected_Component) |
| loop |
| Call := Prefix (Call); |
| end loop; |
| |
| if Nkind (Call) = N_Function_Call then |
| Indices := Parameter_Associations (Call); |
| Pref := Remove_Head (Indices); |
| Set_Expressions (N, Indices); |
| Set_Prefix (N, Pref); |
| end if; |
| |
| else |
| Rewrite (N, Indexing); |
| Resolve (N, Typ); |
| end if; |
| end Resolve_Generalized_Indexing; |
| |
| --------------------------- |
| -- Resolve_If_Expression -- |
| --------------------------- |
| |
| procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id) is |
| Condition : constant Node_Id := First (Expressions (N)); |
| Then_Expr : constant Node_Id := Next (Condition); |
| Else_Expr : Node_Id := Next (Then_Expr); |
| Else_Typ : Entity_Id; |
| Then_Typ : Entity_Id; |
| |
| begin |
| Resolve (Condition, Any_Boolean); |
| Resolve (Then_Expr, Typ); |
| Then_Typ := Etype (Then_Expr); |
| |
| -- When the "then" expression is of a scalar subtype different from the |
| -- result subtype, then insert a conversion to ensure the generation of |
| -- a constraint check. The same is done for the else part below, again |
| -- comparing subtypes rather than base types. |
| |
| if Is_Scalar_Type (Then_Typ) |
| and then Then_Typ /= Typ |
| then |
| Rewrite (Then_Expr, Convert_To (Typ, Then_Expr)); |
| Analyze_And_Resolve (Then_Expr, Typ); |
| end if; |
| |
| -- If ELSE expression present, just resolve using the determined type |
| |
| if Present (Else_Expr) then |
| Resolve (Else_Expr, Typ); |
| Else_Typ := Etype (Else_Expr); |
| |
| if Is_Scalar_Type (Else_Typ) |
| and then Else_Typ /= Typ |
| then |
| Rewrite (Else_Expr, Convert_To (Typ, Else_Expr)); |
| Analyze_And_Resolve (Else_Expr, Typ); |
| end if; |
| |
| -- If no ELSE expression is present, root type must be Standard.Boolean |
| -- and we provide a Standard.True result converted to the appropriate |
| -- Boolean type (in case it is a derived boolean type). |
| |
| elsif Root_Type (Typ) = Standard_Boolean then |
| Else_Expr := |
| Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N))); |
| Analyze_And_Resolve (Else_Expr, Typ); |
| Append_To (Expressions (N), Else_Expr); |
| |
| else |
| Error_Msg_N ("can only omit ELSE expression in Boolean case", N); |
| Append_To (Expressions (N), Error); |
| end if; |
| |
| Set_Etype (N, Typ); |
| Eval_If_Expression (N); |
| end Resolve_If_Expression; |
| |
| ------------------------------- |
| -- Resolve_Indexed_Component -- |
| ------------------------------- |
| |
| procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is |
| Name : constant Node_Id := Prefix (N); |
| Expr : Node_Id; |
| Array_Type : Entity_Id := Empty; -- to prevent junk warning |
| Index : Node_Id; |
| |
| begin |
| if Present (Generalized_Indexing (N)) then |
| Resolve_Generalized_Indexing (N, Typ); |
| return; |
| end if; |
| |
| if Is_Overloaded (Name) then |
| |
| -- Use the context type to select the prefix that yields the correct |
| -- component type. |
| |
| declare |
| I : Interp_Index; |
| It : Interp; |
| I1 : Interp_Index := 0; |
| P : constant Node_Id := Prefix (N); |
| Found : Boolean := False; |
| |
| begin |
| Get_First_Interp (P, I, It); |
| while Present (It.Typ) loop |
| if (Is_Array_Type (It.Typ) |
| and then Covers (Typ, Component_Type (It.Typ))) |
| or else (Is_Access_Type (It.Typ) |
| and then Is_Array_Type (Designated_Type (It.Typ)) |
| and then |
| Covers |
| (Typ, |
| Component_Type (Designated_Type (It.Typ)))) |
| then |
| if Found then |
| It := Disambiguate (P, I1, I, Any_Type); |
| |
| if It = No_Interp then |
| Error_Msg_N ("ambiguous prefix for indexing", N); |
| Set_Etype (N, Typ); |
| return; |
| |
| else |
| Found := True; |
| Array_Type := It.Typ; |
| I1 := I; |
| end if; |
| |
| else |
| Found := True; |
| Array_Type := It.Typ; |
| I1 := I; |
| end if; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end; |
| |
| else |
| Array_Type := Etype (Name); |
| end if; |
| |
| Resolve (Name, Array_Type); |
| Array_Type := Get_Actual_Subtype_If_Available (Name); |
| |
| -- If prefix is access type, dereference to get real array type. |
| -- Note: we do not apply an access check because the expander always |
| -- introduces an explicit dereference, and the check will happen there. |
| |
| if Is_Access_Type (Array_Type) then |
| Array_Type := Designated_Type (Array_Type); |
| end if; |
| |
| -- If name was overloaded, set component type correctly now |
| -- If a misplaced call to an entry family (which has no index types) |
| -- return. Error will be diagnosed from calling context. |
| |
| if Is_Array_Type (Array_Type) then |
| Set_Etype (N, Component_Type (Array_Type)); |
| else |
| return; |
| end if; |
| |
| Index := First_Index (Array_Type); |
| Expr := First (Expressions (N)); |
| |
| -- The prefix may have resolved to a string literal, in which case its |
| -- etype has a special representation. This is only possible currently |
| -- if the prefix is a static concatenation, written in functional |
| -- notation. |
| |
| if Ekind (Array_Type) = E_String_Literal_Subtype then |
| Resolve (Expr, Standard_Positive); |
| |
| else |
| while Present (Index) and Present (Expr) loop |
| Resolve (Expr, Etype (Index)); |
| Check_Unset_Reference (Expr); |
| |
| if Is_Scalar_Type (Etype (Expr)) then |
| Apply_Scalar_Range_Check (Expr, Etype (Index)); |
| else |
| Apply_Range_Check (Expr, Get_Actual_Subtype (Index)); |
| end if; |
| |
| Next_Index (Index); |
| Next (Expr); |
| end loop; |
| end if; |
| |
| Analyze_Dimension (N); |
| |
| -- Do not generate the warning on suspicious index if we are analyzing |
| -- package Ada.Tags; otherwise we will report the warning with the |
| -- Prims_Ptr field of the dispatch table. |
| |
| if Scope (Etype (Prefix (N))) = Standard_Standard |
| or else not |
| Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))), |
| Ada_Tags) |
| then |
| Warn_On_Suspicious_Index (Name, First (Expressions (N))); |
| Eval_Indexed_Component (N); |
| end if; |
| |
| -- If the array type is atomic, and is packed, and we are in a left side |
| -- context, then this is worth a warning, since we have a situation |
| -- where the access to the component may cause extra read/writes of |
| -- the atomic array object, which could be considered unexpected. |
| |
| if Nkind (N) = N_Indexed_Component |
| and then (Is_Atomic (Array_Type) |
| or else (Is_Entity_Name (Prefix (N)) |
| and then Is_Atomic (Entity (Prefix (N))))) |
| and then Is_Bit_Packed_Array (Array_Type) |
| and then Is_LHS (N) = Yes |
| then |
| Error_Msg_N ("??assignment to component of packed atomic array", |
| Prefix (N)); |
| Error_Msg_N ("??\may cause unexpected accesses to atomic object", |
| Prefix (N)); |
| end if; |
| end Resolve_Indexed_Component; |
| |
| ----------------------------- |
| -- Resolve_Integer_Literal -- |
| ----------------------------- |
| |
| procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is |
| begin |
| Set_Etype (N, Typ); |
| Eval_Integer_Literal (N); |
| end Resolve_Integer_Literal; |
| |
| -------------------------------- |
| -- Resolve_Intrinsic_Operator -- |
| -------------------------------- |
| |
| procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is |
| Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ)); |
| Op : Entity_Id; |
| Orig_Op : constant Entity_Id := Entity (N); |
| Arg1 : Node_Id; |
| Arg2 : Node_Id; |
| |
| function Convert_Operand (Opnd : Node_Id) return Node_Id; |
| -- If the operand is a literal, it cannot be the expression in a |
| -- conversion. Use a qualified expression instead. |
| |
| function Convert_Operand (Opnd : Node_Id) return Node_Id is |
| Loc : constant Source_Ptr := Sloc (Opnd); |
| Res : Node_Id; |
| begin |
| if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then |
| Res := |
| Make_Qualified_Expression (Loc, |
| Subtype_Mark => New_Occurrence_Of (Btyp, Loc), |
| Expression => Relocate_Node (Opnd)); |
| Analyze (Res); |
| |
| else |
| Res := Unchecked_Convert_To (Btyp, Opnd); |
| end if; |
| |
| return Res; |
| end Convert_Operand; |
| |
| -- Start of processing for Resolve_Intrinsic_Operator |
| |
| begin |
| -- We must preserve the original entity in a generic setting, so that |
| -- the legality of the operation can be verified in an instance. |
| |
| if not Expander_Active then |
| return; |
| end if; |
| |
| Op := Entity (N); |
| while Scope (Op) /= Standard_Standard loop |
| Op := Homonym (Op); |
| pragma Assert (Present (Op)); |
| end loop; |
| |
| Set_Entity (N, Op); |
| Set_Is_Overloaded (N, False); |
| |
| -- If the result or operand types are private, rewrite with unchecked |
| -- conversions on the operands and the result, to expose the proper |
| -- underlying numeric type. |
| |
| if Is_Private_Type (Typ) |
| or else Is_Private_Type (Etype (Left_Opnd (N))) |
| or else Is_Private_Type (Etype (Right_Opnd (N))) |
| then |
| Arg1 := Convert_Operand (Left_Opnd (N)); |
| -- Unchecked_Convert_To (Btyp, Left_Opnd (N)); |
| -- What on earth is this commented out fragment of code??? |
| |
| if Nkind (N) = N_Op_Expon then |
| Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N)); |
| else |
| Arg2 := Convert_Operand (Right_Opnd (N)); |
| end if; |
| |
| if Nkind (Arg1) = N_Type_Conversion then |
| Save_Interps (Left_Opnd (N), Expression (Arg1)); |
| end if; |
| |
| if Nkind (Arg2) = N_Type_Conversion then |
| Save_Interps (Right_Opnd (N), Expression (Arg2)); |
| end if; |
| |
| Set_Left_Opnd (N, Arg1); |
| Set_Right_Opnd (N, Arg2); |
| |
| Set_Etype (N, Btyp); |
| Rewrite (N, Unchecked_Convert_To (Typ, N)); |
| Resolve (N, Typ); |
| |
| elsif Typ /= Etype (Left_Opnd (N)) |
| or else Typ /= Etype (Right_Opnd (N)) |
| then |
| -- Add explicit conversion where needed, and save interpretations in |
| -- case operands are overloaded. If the context is a VMS operation, |
| -- assert that the conversion is legal (the operands have the proper |
| -- types to select the VMS intrinsic). Note that in rare cases the |
| -- VMS operators may be visible, but the default System is being used |
| -- and Address is a private type. |
| |
| Arg1 := Convert_To (Typ, Left_Opnd (N)); |
| Arg2 := Convert_To (Typ, Right_Opnd (N)); |
| |
| if Nkind (Arg1) = N_Type_Conversion then |
| Save_Interps (Left_Opnd (N), Expression (Arg1)); |
| |
| if Is_VMS_Operator (Orig_Op) then |
| Set_Conversion_OK (Arg1); |
| end if; |
| else |
| Save_Interps (Left_Opnd (N), Arg1); |
| end if; |
| |
| if Nkind (Arg2) = N_Type_Conversion then |
| Save_Interps (Right_Opnd (N), Expression (Arg2)); |
| |
| if Is_VMS_Operator (Orig_Op) then |
| Set_Conversion_OK (Arg2); |
| end if; |
| else |
| Save_Interps (Right_Opnd (N), Arg2); |
| end if; |
| |
| Rewrite (Left_Opnd (N), Arg1); |
| Rewrite (Right_Opnd (N), Arg2); |
| Analyze (Arg1); |
| Analyze (Arg2); |
| Resolve_Arithmetic_Op (N, Typ); |
| |
| else |
| Resolve_Arithmetic_Op (N, Typ); |
| end if; |
| end Resolve_Intrinsic_Operator; |
| |
| -------------------------------------- |
| -- Resolve_Intrinsic_Unary_Operator -- |
| -------------------------------------- |
| |
| procedure Resolve_Intrinsic_Unary_Operator |
| (N : Node_Id; |
| Typ : Entity_Id) |
| is |
| Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ)); |
| Op : Entity_Id; |
| Arg2 : Node_Id; |
| |
| begin |
| Op := Entity (N); |
| while Scope (Op) /= Standard_Standard loop |
| Op := Homonym (Op); |
| pragma Assert (Present (Op)); |
| end loop; |
| |
| Set_Entity (N, Op); |
| |
| if Is_Private_Type (Typ) then |
| Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N)); |
| Save_Interps (Right_Opnd (N), Expression (Arg2)); |
| |
| Set_Right_Opnd (N, Arg2); |
| |
| Set_Etype (N, Btyp); |
| Rewrite (N, Unchecked_Convert_To (Typ, N)); |
| Resolve (N, Typ); |
| |
| else |
| Resolve_Unary_Op (N, Typ); |
| end if; |
| end Resolve_Intrinsic_Unary_Operator; |
| |
| ------------------------ |
| -- Resolve_Logical_Op -- |
| ------------------------ |
| |
| procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : Entity_Id; |
| |
| begin |
| Check_No_Direct_Boolean_Operators (N); |
| |
| -- Predefined operations on scalar types yield the base type. On the |
| -- other hand, logical operations on arrays yield the type of the |
| -- arguments (and the context). |
| |
| if Is_Array_Type (Typ) then |
| B_Typ := Typ; |
| else |
| B_Typ := Base_Type (Typ); |
| end if; |
| |
| -- OK if this is a VMS-specific intrinsic operation |
| |
| if Is_VMS_Operator (Entity (N)) then |
| null; |
| |
| -- The following test is required because the operands of the operation |
| -- may be literals, in which case the resulting type appears to be |
| -- compatible with a signed integer type, when in fact it is compatible |
| -- only with modular types. If the context itself is universal, the |
| -- operation is illegal. |
| |
| elsif not Valid_Boolean_Arg (Typ) then |
| Error_Msg_N ("invalid context for logical operation", N); |
| Set_Etype (N, Any_Type); |
| return; |
| |
| elsif Typ = Any_Modular then |
| Error_Msg_N |
| ("no modular type available in this context", N); |
| Set_Etype (N, Any_Type); |
| return; |
| |
| elsif Is_Modular_Integer_Type (Typ) |
| and then Etype (Left_Opnd (N)) = Universal_Integer |
| and then Etype (Right_Opnd (N)) = Universal_Integer |
| then |
| Check_For_Visible_Operator (N, B_Typ); |
| end if; |
| |
| -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or |
| -- is active and the result type is standard Boolean (do not mess with |
| -- ops that return a nonstandard Boolean type, because something strange |
| -- is going on). |
| |
| -- Note: you might expect this replacement to be done during expansion, |
| -- but that doesn't work, because when the pragma Short_Circuit_And_Or |
| -- is used, no part of the right operand of an "and" or "or" operator |
| -- should be executed if the left operand would short-circuit the |
| -- evaluation of the corresponding "and then" or "or else". If we left |
| -- the replacement to expansion time, then run-time checks associated |
| -- with such operands would be evaluated unconditionally, due to being |
| -- before the condition prior to the rewriting as short-circuit forms |
| -- during expansion. |
| |
| if Short_Circuit_And_Or |
| and then B_Typ = Standard_Boolean |
| and then Nkind_In (N, N_Op_And, N_Op_Or) |
| then |
| if Nkind (N) = N_Op_And then |
| Rewrite (N, |
| Make_And_Then (Sloc (N), |
| Left_Opnd => Relocate_Node (Left_Opnd (N)), |
| Right_Opnd => Relocate_Node (Right_Opnd (N)))); |
| Analyze_And_Resolve (N, B_Typ); |
| |
| -- Case of OR changed to OR ELSE |
| |
| else |
| Rewrite (N, |
| Make_Or_Else (Sloc (N), |
| Left_Opnd => Relocate_Node (Left_Opnd (N)), |
| Right_Opnd => Relocate_Node (Right_Opnd (N)))); |
| Analyze_And_Resolve (N, B_Typ); |
| end if; |
| |
| -- Return now, since analysis of the rewritten ops will take care of |
| -- other reference bookkeeping and expression folding. |
| |
| return; |
| end if; |
| |
| Resolve (Left_Opnd (N), B_Typ); |
| Resolve (Right_Opnd (N), B_Typ); |
| |
| Check_Unset_Reference (Left_Opnd (N)); |
| Check_Unset_Reference (Right_Opnd (N)); |
| |
| Set_Etype (N, B_Typ); |
| Generate_Operator_Reference (N, B_Typ); |
| Eval_Logical_Op (N); |
| |
| -- In SPARK, logical operations AND, OR and XOR for arrays are defined |
| -- only when both operands have same static lower and higher bounds. Of |
| -- course the types have to match, so only check if operands are |
| -- compatible and the node itself has no errors. |
| |
| if Is_Array_Type (B_Typ) |
| and then Nkind (N) in N_Binary_Op |
| then |
| declare |
| Left_Typ : constant Node_Id := Etype (Left_Opnd (N)); |
| Right_Typ : constant Node_Id := Etype (Right_Opnd (N)); |
| |
| begin |
| -- Protect call to Matching_Static_Array_Bounds to avoid costly |
| -- operation if not needed. |
| |
| if Restriction_Check_Required (SPARK_05) |
| and then Base_Type (Left_Typ) = Base_Type (Right_Typ) |
| and then Left_Typ /= Any_Composite -- or Left_Opnd in error |
| and then Right_Typ /= Any_Composite -- or Right_Opnd in error |
| and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ) |
| then |
| Check_SPARK_Restriction |
| ("array types should have matching static bounds", N); |
| end if; |
| end; |
| end if; |
| |
| Check_Function_Writable_Actuals (N); |
| end Resolve_Logical_Op; |
| |
| --------------------------- |
| -- Resolve_Membership_Op -- |
| --------------------------- |
| |
| -- The context can only be a boolean type, and does not determine the |
| -- arguments. Arguments should be unambiguous, but the preference rule for |
| -- universal types applies. |
| |
| procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is |
| pragma Warnings (Off, Typ); |
| |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| T : Entity_Id; |
| |
| procedure Resolve_Set_Membership; |
| -- Analysis has determined a unique type for the left operand. Use it to |
| -- resolve the disjuncts. |
| |
| ---------------------------- |
| -- Resolve_Set_Membership -- |
| ---------------------------- |
| |
| procedure Resolve_Set_Membership is |
| Alt : Node_Id; |
| Ltyp : constant Entity_Id := Etype (L); |
| |
| begin |
| Resolve (L, Ltyp); |
| |
| Alt := First (Alternatives (N)); |
| while Present (Alt) loop |
| |
| -- Alternative is an expression, a range |
| -- or a subtype mark. |
| |
| if not Is_Entity_Name (Alt) |
| or else not Is_Type (Entity (Alt)) |
| then |
| Resolve (Alt, Ltyp); |
| end if; |
| |
| Next (Alt); |
| end loop; |
| |
| -- Check for duplicates for discrete case |
| |
| if Is_Discrete_Type (Ltyp) then |
| declare |
| type Ent is record |
| Alt : Node_Id; |
| Val : Uint; |
| end record; |
| |
| Alts : array (0 .. List_Length (Alternatives (N))) of Ent; |
| Nalts : Nat; |
| |
| begin |
| -- Loop checking duplicates. This is quadratic, but giant sets |
| -- are unlikely in this context so it's a reasonable choice. |
| |
| Nalts := 0; |
| Alt := First (Alternatives (N)); |
| while Present (Alt) loop |
| if Is_Static_Expression (Alt) |
| and then (Nkind_In (Alt, N_Integer_Literal, |
| N_Character_Literal) |
| or else Nkind (Alt) in N_Has_Entity) |
| then |
| Nalts := Nalts + 1; |
| Alts (Nalts) := (Alt, Expr_Value (Alt)); |
| |
| for J in 1 .. Nalts - 1 loop |
| if Alts (J).Val = Alts (Nalts).Val then |
| Error_Msg_Sloc := Sloc (Alts (J).Alt); |
| Error_Msg_N ("duplicate of value given#??", Alt); |
| end if; |
| end loop; |
| end if; |
| |
| Alt := Next (Alt); |
| end loop; |
| end; |
| end if; |
| end Resolve_Set_Membership; |
| |
| -- Start of processing for Resolve_Membership_Op |
| |
| begin |
| if L = Error or else R = Error then |
| return; |
| end if; |
| |
| if Present (Alternatives (N)) then |
| Resolve_Set_Membership; |
| Check_Function_Writable_Actuals (N); |
| return; |
| |
| elsif not Is_Overloaded (R) |
| and then |
| (Etype (R) = Universal_Integer |
| or else |
| Etype (R) = Universal_Real) |
| and then Is_Overloaded (L) |
| then |
| T := Etype (R); |
| |
| -- Ada 2005 (AI-251): Support the following case: |
| |
| -- type I is interface; |
| -- type T is tagged ... |
| |
| -- function Test (O : I'Class) is |
| -- begin |
| -- return O in T'Class. |
| -- end Test; |
| |
| -- In this case we have nothing else to do. The membership test will be |
| -- done at run time. |
| |
| elsif Ada_Version >= Ada_2005 |
| and then Is_Class_Wide_Type (Etype (L)) |
| and then Is_Interface (Etype (L)) |
| and then Is_Class_Wide_Type (Etype (R)) |
| and then not Is_Interface (Etype (R)) |
| then |
| return; |
| else |
| T := Intersect_Types (L, R); |
| end if; |
| |
| -- If mixed-mode operations are present and operands are all literal, |
| -- the only interpretation involves Duration, which is probably not |
| -- the intention of the programmer. |
| |
| if T = Any_Fixed then |
| T := Unique_Fixed_Point_Type (N); |
| |
| if T = Any_Type then |
| return; |
| end if; |
| end if; |
| |
| Resolve (L, T); |
| Check_Unset_Reference (L); |
| |
| if Nkind (R) = N_Range |
| and then not Is_Scalar_Type (T) |
| then |
| Error_Msg_N ("scalar type required for range", R); |
| end if; |
| |
| if Is_Entity_Name (R) then |
| Freeze_Expression (R); |
| else |
| Resolve (R, T); |
| Check_Unset_Reference (R); |
| end if; |
| |
| Eval_Membership_Op (N); |
| Check_Function_Writable_Actuals (N); |
| end Resolve_Membership_Op; |
| |
| ------------------ |
| -- Resolve_Null -- |
| ------------------ |
| |
| procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| |
| begin |
| -- Handle restriction against anonymous null access values This |
| -- restriction can be turned off using -gnatdj. |
| |
| -- Ada 2005 (AI-231): Remove restriction |
| |
| if Ada_Version < Ada_2005 |
| and then not Debug_Flag_J |
| and then Ekind (Typ) = E_Anonymous_Access_Type |
| and then Comes_From_Source (N) |
| then |
| -- In the common case of a call which uses an explicitly null value |
| -- for an access parameter, give specialized error message. |
| |
| if Nkind (Parent (N)) in N_Subprogram_Call then |
| Error_Msg_N |
| ("null is not allowed as argument for an access parameter", N); |
| |
| -- Standard message for all other cases (are there any?) |
| |
| else |
| Error_Msg_N |
| ("null cannot be of an anonymous access type", N); |
| end if; |
| end if; |
| |
| -- Ada 2005 (AI-231): Generate the null-excluding check in case of |
| -- assignment to a null-excluding object |
| |
| if Ada_Version >= Ada_2005 |
| and then Can_Never_Be_Null (Typ) |
| and then Nkind (Parent (N)) = N_Assignment_Statement |
| then |
| if not Inside_Init_Proc then |
| Insert_Action |
| (Compile_Time_Constraint_Error (N, |
| "(Ada 2005) null not allowed in null-excluding objects??"), |
| Make_Raise_Constraint_Error (Loc, |
| Reason => CE_Access_Check_Failed)); |
| else |
| Insert_Action (N, |
| Make_Raise_Constraint_Error (Loc, |
| Reason => CE_Access_Check_Failed)); |
| end if; |
| end if; |
| |
| -- In a distributed context, null for a remote access to subprogram may |
| -- need to be replaced with a special record aggregate. In this case, |
| -- return after having done the transformation. |
| |
| if (Ekind (Typ) = E_Record_Type |
| or else Is_Remote_Access_To_Subprogram_Type (Typ)) |
| and then Remote_AST_Null_Value (N, Typ) |
| then |
| return; |
| end if; |
| |
| -- The null literal takes its type from the context |
| |
| Set_Etype (N, Typ); |
| end Resolve_Null; |
| |
| ----------------------- |
| -- Resolve_Op_Concat -- |
| ----------------------- |
| |
| procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is |
| |
| -- We wish to avoid deep recursion, because concatenations are often |
| -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left |
| -- operands nonrecursively until we find something that is not a simple |
| -- concatenation (A in this case). We resolve that, and then walk back |
| -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest |
| -- to do the rest of the work at each level. The Parent pointers allow |
| -- us to avoid recursion, and thus avoid running out of memory. See also |
| -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used. |
| |
| NN : Node_Id := N; |
| Op1 : Node_Id; |
| |
| begin |
| -- The following code is equivalent to: |
| |
| -- Resolve_Op_Concat_First (NN, Typ); |
| -- Resolve_Op_Concat_Arg (N, ...); |
| -- Resolve_Op_Concat_Rest (N, Typ); |
| |
| -- where the Resolve_Op_Concat_Arg call recurses back here if the left |
| -- operand is a concatenation. |
| |
| -- Walk down left operands |
| |
| loop |
| Resolve_Op_Concat_First (NN, Typ); |
| Op1 := Left_Opnd (NN); |
| exit when not (Nkind (Op1) = N_Op_Concat |
| and then not Is_Array_Type (Component_Type (Typ)) |
| and then Entity (Op1) = Entity (NN)); |
| NN := Op1; |
| end loop; |
| |
| -- Now (given the above example) NN is A&B and Op1 is A |
| |
| -- First resolve Op1 ... |
| |
| Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN)); |
| |
| -- ... then walk NN back up until we reach N (where we started), calling |
| -- Resolve_Op_Concat_Rest along the way. |
| |
| loop |
| Resolve_Op_Concat_Rest (NN, Typ); |
| exit when NN = N; |
| NN := Parent (NN); |
| end loop; |
| |
| if Base_Type (Etype (N)) /= Standard_String then |
| Check_SPARK_Restriction |
| ("result of concatenation should have type String", N); |
| end if; |
| end Resolve_Op_Concat; |
| |
| --------------------------- |
| -- Resolve_Op_Concat_Arg -- |
| --------------------------- |
| |
| procedure Resolve_Op_Concat_Arg |
| (N : Node_Id; |
| Arg : Node_Id; |
| Typ : Entity_Id; |
| Is_Comp : Boolean) |
| is |
| Btyp : constant Entity_Id := Base_Type (Typ); |
| Ctyp : constant Entity_Id := Component_Type (Typ); |
| |
| begin |
| if In_Instance then |
| if Is_Comp |
| or else (not Is_Overloaded (Arg) |
| and then Etype (Arg) /= Any_Composite |
| and then Covers (Ctyp, Etype (Arg))) |
| then |
| Resolve (Arg, Ctyp); |
| else |
| Resolve (Arg, Btyp); |
| end if; |
| |
| -- If both Array & Array and Array & Component are visible, there is a |
| -- potential ambiguity that must be reported. |
| |
| elsif Has_Compatible_Type (Arg, Ctyp) then |
| if Nkind (Arg) = N_Aggregate |
| and then Is_Composite_Type (Ctyp) |
| then |
| if Is_Private_Type (Ctyp) then |
| Resolve (Arg, Btyp); |
| |
| -- If the operation is user-defined and not overloaded use its |
| -- profile. The operation may be a renaming, in which case it has |
| -- been rewritten, and we want the original profile. |
| |
| elsif not Is_Overloaded (N) |
| and then Comes_From_Source (Entity (Original_Node (N))) |
| and then Ekind (Entity (Original_Node (N))) = E_Function |
| then |
| Resolve (Arg, |
| Etype |
| (Next_Formal (First_Formal (Entity (Original_Node (N)))))); |
| return; |
| |
| -- Otherwise an aggregate may match both the array type and the |
| -- component type. |
| |
| else |
| Error_Msg_N ("ambiguous aggregate must be qualified", Arg); |
| Set_Etype (Arg, Any_Type); |
| end if; |
| |
| else |
| if Is_Overloaded (Arg) |
| and then Has_Compatible_Type (Arg, Typ) |
| and then Etype (Arg) /= Any_Type |
| then |
| declare |
| I : Interp_Index; |
| It : Interp; |
| Func : Entity_Id; |
| |
| begin |
| Get_First_Interp (Arg, I, It); |
| Func := It.Nam; |
| Get_Next_Interp (I, It); |
| |
| -- Special-case the error message when the overloading is |
| -- caused by a function that yields an array and can be |
| -- called without parameters. |
| |
| if It.Nam = Func then |
| Error_Msg_Sloc := Sloc (Func); |
| Error_Msg_N ("ambiguous call to function#", Arg); |
| Error_Msg_NE |
| ("\\interpretation as call yields&", Arg, Typ); |
| Error_Msg_NE |
| ("\\interpretation as indexing of call yields&", |
| Arg, Component_Type (Typ)); |
| |
| else |
| Error_Msg_N ("ambiguous operand for concatenation!", Arg); |
| |
| Get_First_Interp (Arg, I, It); |
| while Present (It.Nam) loop |
| Error_Msg_Sloc := Sloc (It.Nam); |
| |
| if Base_Type (It.Typ) = Btyp |
| or else |
| Base_Type (It.Typ) = Base_Type (Ctyp) |
| then |
| Error_Msg_N -- CODEFIX |
| ("\\possible interpretation#", Arg); |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end if; |
| end; |
| end if; |
| |
| Resolve (Arg, Component_Type (Typ)); |
| |
| if Nkind (Arg) = N_String_Literal then |
| Set_Etype (Arg, Component_Type (Typ)); |
| end if; |
| |
| if Arg = Left_Opnd (N) then |
| Set_Is_Component_Left_Opnd (N); |
| else |
| Set_Is_Component_Right_Opnd (N); |
| end if; |
| end if; |
| |
| else |
| Resolve (Arg, Btyp); |
| end if; |
| |
| -- Concatenation is restricted in SPARK: each operand must be either a |
| -- string literal, the name of a string constant, a static character or |
| -- string expression, or another concatenation. Arg cannot be a |
| -- concatenation here as callers of Resolve_Op_Concat_Arg call it |
| -- separately on each final operand, past concatenation operations. |
| |
| if Is_Character_Type (Etype (Arg)) then |
| if not Is_Static_Expression (Arg) then |
| Check_SPARK_Restriction |
| ("character operand for concatenation should be static", Arg); |
| end if; |
| |
| elsif Is_String_Type (Etype (Arg)) then |
| if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name) |
| and then Is_Constant_Object (Entity (Arg))) |
| and then not Is_Static_Expression (Arg) |
| then |
| Check_SPARK_Restriction |
| ("string operand for concatenation should be static", Arg); |
| end if; |
| |
| -- Do not issue error on an operand that is neither a character nor a |
| -- string, as the error is issued in Resolve_Op_Concat. |
| |
| else |
| null; |
| end if; |
| |
| Check_Unset_Reference (Arg); |
| end Resolve_Op_Concat_Arg; |
| |
| ----------------------------- |
| -- Resolve_Op_Concat_First -- |
| ----------------------------- |
| |
| procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is |
| Btyp : constant Entity_Id := Base_Type (Typ); |
| Op1 : constant Node_Id := Left_Opnd (N); |
| Op2 : constant Node_Id := Right_Opnd (N); |
| |
| begin |
| -- The parser folds an enormous sequence of concatenations of string |
| -- literals into "" & "...", where the Is_Folded_In_Parser flag is set |
| -- in the right operand. If the expression resolves to a predefined "&" |
| -- operator, all is well. Otherwise, the parser's folding is wrong, so |
| -- we give an error. See P_Simple_Expression in Par.Ch4. |
| |
| if Nkind (Op2) = N_String_Literal |
| and then Is_Folded_In_Parser (Op2) |
| and then Ekind (Entity (N)) = E_Function |
| then |
| pragma Assert (Nkind (Op1) = N_String_Literal -- should be "" |
| and then String_Length (Strval (Op1)) = 0); |
| Error_Msg_N ("too many user-defined concatenations", N); |
| return; |
| end if; |
| |
| Set_Etype (N, Btyp); |
| |
| if Is_Limited_Composite (Btyp) then |
| Error_Msg_N ("concatenation not available for limited array", N); |
| Explain_Limited_Type (Btyp, N); |
| end if; |
| end Resolve_Op_Concat_First; |
| |
| ---------------------------- |
| -- Resolve_Op_Concat_Rest -- |
| ---------------------------- |
| |
| procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is |
| Op1 : constant Node_Id := Left_Opnd (N); |
| Op2 : constant Node_Id := Right_Opnd (N); |
| |
| begin |
| Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N)); |
| |
| Generate_Operator_Reference (N, Typ); |
| |
| if Is_String_Type (Typ) then |
| Eval_Concatenation (N); |
| end if; |
| |
| -- If this is not a static concatenation, but the result is a string |
| -- type (and not an array of strings) ensure that static string operands |
| -- have their subtypes properly constructed. |
| |
| if Nkind (N) /= N_String_Literal |
| and then Is_Character_Type (Component_Type (Typ)) |
| then |
| Set_String_Literal_Subtype (Op1, Typ); |
| Set_String_Literal_Subtype (Op2, Typ); |
| end if; |
| end Resolve_Op_Concat_Rest; |
| |
| ---------------------- |
| -- Resolve_Op_Expon -- |
| ---------------------- |
| |
| procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| |
| begin |
| -- Catch attempts to do fixed-point exponentiation with universal |
| -- operands, which is a case where the illegality is not caught during |
| -- normal operator analysis. This is not done in preanalysis mode |
| -- since the tree is not fully decorated during preanalysis. |
| |
| if Full_Analysis then |
| if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then |
| Error_Msg_N ("exponentiation not available for fixed point", N); |
| return; |
| |
| elsif Nkind (Parent (N)) in N_Op |
| and then Is_Fixed_Point_Type (Etype (Parent (N))) |
| and then Etype (N) = Universal_Real |
| and then Comes_From_Source (N) |
| then |
| Error_Msg_N ("exponentiation not available for fixed point", N); |
| return; |
| end if; |
| end if; |
| |
| if Comes_From_Source (N) |
| and then Ekind (Entity (N)) = E_Function |
| and then Is_Imported (Entity (N)) |
| and then Is_Intrinsic_Subprogram (Entity (N)) |
| then |
| Resolve_Intrinsic_Operator (N, Typ); |
| return; |
| end if; |
| |
| if Etype (Left_Opnd (N)) = Universal_Integer |
| or else Etype (Left_Opnd (N)) = Universal_Real |
| then |
| Check_For_Visible_Operator (N, B_Typ); |
| end if; |
| |
| -- We do the resolution using the base type, because intermediate values |
| -- in expressions are always of the base type, not a subtype of it. |
| |
| Resolve (Left_Opnd (N), B_Typ); |
| Resolve (Right_Opnd (N), Standard_Integer); |
| |
| -- For integer types, right argument must be in Natural range |
| |
| if Is_Integer_Type (Typ) then |
| Apply_Scalar_Range_Check (Right_Opnd (N), Standard_Natural); |
| end if; |
| |
| Check_Unset_Reference (Left_Opnd (N)); |
| Check_Unset_Reference (Right_Opnd (N)); |
| |
| Set_Etype (N, B_Typ); |
| Generate_Operator_Reference (N, B_Typ); |
| |
| Analyze_Dimension (N); |
| |
| if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then |
| -- Evaluate the exponentiation operator for dimensioned type |
| |
| Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ); |
| else |
| Eval_Op_Expon (N); |
| end if; |
| |
| -- Set overflow checking bit. Much cleverer code needed here eventually |
| -- and perhaps the Resolve routines should be separated for the various |
| -- arithmetic operations, since they will need different processing. ??? |
| |
| if Nkind (N) in N_Op then |
| if not Overflow_Checks_Suppressed (Etype (N)) then |
| Enable_Overflow_Check (N); |
| end if; |
| end if; |
| end Resolve_Op_Expon; |
| |
| -------------------- |
| -- Resolve_Op_Not -- |
| -------------------- |
| |
| procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : Entity_Id; |
| |
| function Parent_Is_Boolean return Boolean; |
| -- This function determines if the parent node is a boolean operator or |
| -- operation (comparison op, membership test, or short circuit form) and |
| -- the not in question is the left operand of this operation. Note that |
| -- if the not is in parens, then false is returned. |
| |
| ----------------------- |
| -- Parent_Is_Boolean -- |
| ----------------------- |
| |
| function Parent_Is_Boolean return Boolean is |
| begin |
| if Paren_Count (N) /= 0 then |
| return False; |
| |
| else |
| case Nkind (Parent (N)) is |
| when N_Op_And | |
| N_Op_Eq | |
| N_Op_Ge | |
| N_Op_Gt | |
| N_Op_Le | |
| N_Op_Lt | |
| N_Op_Ne | |
| N_Op_Or | |
| N_Op_Xor | |
| N_In | |
| N_Not_In | |
| N_And_Then | |
| N_Or_Else => |
| |
| return Left_Opnd (Parent (N)) = N; |
| |
| when others => |
| return False; |
| end case; |
| end if; |
| end Parent_Is_Boolean; |
| |
| -- Start of processing for Resolve_Op_Not |
| |
| begin |
| -- Predefined operations on scalar types yield the base type. On the |
| -- other hand, logical operations on arrays yield the type of the |
| -- arguments (and the context). |
| |
| if Is_Array_Type (Typ) then |
| B_Typ := Typ; |
| else |
| B_Typ := Base_Type (Typ); |
| end if; |
| |
| if Is_VMS_Operator (Entity (N)) then |
| null; |
| |
| -- Straightforward case of incorrect arguments |
| |
| elsif not Valid_Boolean_Arg (Typ) then |
| Error_Msg_N ("invalid operand type for operator&", N); |
| Set_Etype (N, Any_Type); |
| return; |
| |
| -- Special case of probable missing parens |
| |
| elsif Typ = Universal_Integer or else Typ = Any_Modular then |
| if Parent_Is_Boolean then |
| Error_Msg_N |
| ("operand of not must be enclosed in parentheses", |
| Right_Opnd (N)); |
| else |
| Error_Msg_N |
| ("no modular type available in this context", N); |
| end if; |
| |
| Set_Etype (N, Any_Type); |
| return; |
| |
| -- OK resolution of NOT |
| |
| else |
| -- Warn if non-boolean types involved. This is a case like not a < b |
| -- where a and b are modular, where we will get (not a) < b and most |
| -- likely not (a < b) was intended. |
| |
| if Warn_On_Questionable_Missing_Parens |
| and then not Is_Boolean_Type (Typ) |
| and then Parent_Is_Boolean |
| then |
| Error_Msg_N ("?q?not expression should be parenthesized here!", N); |
| end if; |
| |
| -- Warn on double negation if checking redundant constructs |
| |
| if Warn_On_Redundant_Constructs |
| and then Comes_From_Source (N) |
| and then Comes_From_Source (Right_Opnd (N)) |
| and then Root_Type (Typ) = Standard_Boolean |
| and then Nkind (Right_Opnd (N)) = N_Op_Not |
| then |
| Error_Msg_N ("redundant double negation?r?", N); |
| end if; |
| |
| -- Complete resolution and evaluation of NOT |
| |
| Resolve (Right_Opnd (N), B_Typ); |
| Check_Unset_Reference (Right_Opnd (N)); |
| Set_Etype (N, B_Typ); |
| Generate_Operator_Reference (N, B_Typ); |
| Eval_Op_Not (N); |
| end if; |
| end Resolve_Op_Not; |
| |
| ----------------------------- |
| -- Resolve_Operator_Symbol -- |
| ----------------------------- |
| |
| -- Nothing to be done, all resolved already |
| |
| procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is |
| pragma Warnings (Off, N); |
| pragma Warnings (Off, Typ); |
| |
| begin |
| null; |
| end Resolve_Operator_Symbol; |
| |
| ---------------------------------- |
| -- Resolve_Qualified_Expression -- |
| ---------------------------------- |
| |
| procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is |
| pragma Warnings (Off, Typ); |
| |
| Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N)); |
| Expr : constant Node_Id := Expression (N); |
| |
| begin |
| Resolve (Expr, Target_Typ); |
| |
| -- Protect call to Matching_Static_Array_Bounds to avoid costly |
| -- operation if not needed. |
| |
| if Restriction_Check_Required (SPARK_05) |
| and then Is_Array_Type (Target_Typ) |
| and then Is_Array_Type (Etype (Expr)) |
| and then Etype (Expr) /= Any_Composite -- or else Expr in error |
| and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr)) |
| then |
| Check_SPARK_Restriction |
| ("array types should have matching static bounds", N); |
| end if; |
| |
| -- A qualified expression requires an exact match of the type, class- |
| -- wide matching is not allowed. However, if the qualifying type is |
| -- specific and the expression has a class-wide type, it may still be |
| -- okay, since it can be the result of the expansion of a call to a |
| -- dispatching function, so we also have to check class-wideness of the |
| -- type of the expression's original node. |
| |
| if (Is_Class_Wide_Type (Target_Typ) |
| or else |
| (Is_Class_Wide_Type (Etype (Expr)) |
| and then Is_Class_Wide_Type (Etype (Original_Node (Expr))))) |
| and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ) |
| then |
| Wrong_Type (Expr, Target_Typ); |
| end if; |
| |
| -- If the target type is unconstrained, then we reset the type of the |
| -- result from the type of the expression. For other cases, the actual |
| -- subtype of the expression is the target type. |
| |
| if Is_Composite_Type (Target_Typ) |
| and then not Is_Constrained (Target_Typ) |
| then |
| Set_Etype (N, Etype (Expr)); |
| end if; |
| |
| Analyze_Dimension (N); |
| Eval_Qualified_Expression (N); |
| end Resolve_Qualified_Expression; |
| |
| ------------------------------ |
| -- Resolve_Raise_Expression -- |
| ------------------------------ |
| |
| procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id) is |
| begin |
| if Typ = Raise_Type then |
| Error_Msg_N ("cannot find unique type for raise expression", N); |
| Set_Etype (N, Any_Type); |
| else |
| Set_Etype (N, Typ); |
| end if; |
| end Resolve_Raise_Expression; |
| |
| ------------------- |
| -- Resolve_Range -- |
| ------------------- |
| |
| procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is |
| L : constant Node_Id := Low_Bound (N); |
| H : constant Node_Id := High_Bound (N); |
| |
| function First_Last_Ref return Boolean; |
| -- Returns True if N is of the form X'First .. X'Last where X is the |
| -- same entity for both attributes. |
| |
| -------------------- |
| -- First_Last_Ref -- |
| -------------------- |
| |
| function First_Last_Ref return Boolean is |
| Lorig : constant Node_Id := Original_Node (L); |
| Horig : constant Node_Id := Original_Node (H); |
| |
| begin |
| if Nkind (Lorig) = N_Attribute_Reference |
| and then Nkind (Horig) = N_Attribute_Reference |
| and then Attribute_Name (Lorig) = Name_First |
| and then Attribute_Name (Horig) = Name_Last |
| then |
| declare |
| PL : constant Node_Id := Prefix (Lorig); |
| PH : constant Node_Id := Prefix (Horig); |
| begin |
| if Is_Entity_Name (PL) |
| and then Is_Entity_Name (PH) |
| and then Entity (PL) = Entity (PH) |
| then |
| return True; |
| end if; |
| end; |
| end if; |
| |
| return False; |
| end First_Last_Ref; |
| |
| -- Start of processing for Resolve_Range |
| |
| begin |
| Set_Etype (N, Typ); |
| Resolve (L, Typ); |
| Resolve (H, Typ); |
| |
| -- Check for inappropriate range on unordered enumeration type |
| |
| if Bad_Unordered_Enumeration_Reference (N, Typ) |
| |
| -- Exclude X'First .. X'Last if X is the same entity for both |
| |
| and then not First_Last_Ref |
| then |
| Error_Msg_Sloc := Sloc (Typ); |
| Error_Msg_NE |
| ("subrange of unordered enumeration type& declared#?U?", N, Typ); |
| end if; |
| |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (H); |
| |
| -- We have to check the bounds for being within the base range as |
| -- required for a non-static context. Normally this is automatic and |
| -- done as part of evaluating expressions, but the N_Range node is an |
| -- exception, since in GNAT we consider this node to be a subexpression, |
| -- even though in Ada it is not. The circuit in Sem_Eval could check for |
| -- this, but that would put the test on the main evaluation path for |
| -- expressions. |
| |
| Check_Non_Static_Context (L); |
| Check_Non_Static_Context (H); |
| |
| -- Check for an ambiguous range over character literals. This will |
| -- happen with a membership test involving only literals. |
| |
| if Typ = Any_Character then |
| Ambiguous_Character (L); |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| -- If bounds are static, constant-fold them, so size computations are |
| -- identical between front-end and back-end. Do not perform this |
| -- transformation while analyzing generic units, as type information |
| -- would be lost when reanalyzing the constant node in the instance. |
| |
| if Is_Discrete_Type (Typ) and then Expander_Active then |
| if Is_OK_Static_Expression (L) then |
| Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L)); |
| end if; |
| |
| if Is_OK_Static_Expression (H) then |
| Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H)); |
| end if; |
| end if; |
| end Resolve_Range; |
| |
| -------------------------- |
| -- Resolve_Real_Literal -- |
| -------------------------- |
| |
| procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is |
| Actual_Typ : constant Entity_Id := Etype (N); |
| |
| begin |
| -- Special processing for fixed-point literals to make sure that the |
| -- value is an exact multiple of small where this is required. We skip |
| -- this for the universal real case, and also for generic types. |
| |
| if Is_Fixed_Point_Type (Typ) |
| and then Typ /= Universal_Fixed |
| and then Typ /= Any_Fixed |
| and then not Is_Generic_Type (Typ) |
| then |
| declare |
| Val : constant Ureal := Realval (N); |
| Cintr : constant Ureal := Val / Small_Value (Typ); |
| Cint : constant Uint := UR_Trunc (Cintr); |
| Den : constant Uint := Norm_Den (Cintr); |
| Stat : Boolean; |
| |
| begin |
| -- Case of literal is not an exact multiple of the Small |
| |
| if Den /= 1 then |
| |
| -- For a source program literal for a decimal fixed-point type, |
| -- this is statically illegal (RM 4.9(36)). |
| |
| if Is_Decimal_Fixed_Point_Type (Typ) |
| and then Actual_Typ = Universal_Real |
| and then Comes_From_Source (N) |
| then |
| Error_Msg_N ("value has extraneous low order digits", N); |
| end if; |
| |
| -- Generate a warning if literal from source |
| |
| if Is_Static_Expression (N) |
| and then Warn_On_Bad_Fixed_Value |
| then |
| Error_Msg_N |
| ("?b?static fixed-point value is not a multiple of Small!", |
| N); |
| end if; |
| |
| -- Replace literal by a value that is the exact representation |
| -- of a value of the type, i.e. a multiple of the small value, |
| -- by truncation, since Machine_Rounds is false for all GNAT |
| -- fixed-point types (RM 4.9(38)). |
| |
| Stat := Is_Static_Expression (N); |
| Rewrite (N, |
| Make_Real_Literal (Sloc (N), |
| Realval => Small_Value (Typ) * Cint)); |
| |
| Set_Is_Static_Expression (N, Stat); |
| end if; |
| |
| -- In all cases, set the corresponding integer field |
| |
| Set_Corresponding_Integer_Value (N, Cint); |
| end; |
| end if; |
| |
| -- Now replace the actual type by the expected type as usual |
| |
| Set_Etype (N, Typ); |
| Eval_Real_Literal (N); |
| end Resolve_Real_Literal; |
| |
| ----------------------- |
| -- Resolve_Reference -- |
| ----------------------- |
| |
| procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is |
| P : constant Node_Id := Prefix (N); |
| |
| begin |
| -- Replace general access with specific type |
| |
| if Ekind (Etype (N)) = E_Allocator_Type then |
| Set_Etype (N, Base_Type (Typ)); |
| end if; |
| |
| Resolve (P, Designated_Type (Etype (N))); |
| |
| -- If we are taking the reference of a volatile entity, then treat it as |
| -- a potential modification of this entity. This is too conservative, |
| -- but necessary because remove side effects can cause transformations |
| -- of normal assignments into reference sequences that otherwise fail to |
| -- notice the modification. |
| |
| if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then |
| Note_Possible_Modification (P, Sure => False); |
| end if; |
| end Resolve_Reference; |
| |
| -------------------------------- |
| -- Resolve_Selected_Component -- |
| -------------------------------- |
| |
| procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is |
| Comp : Entity_Id; |
| Comp1 : Entity_Id := Empty; -- prevent junk warning |
| P : constant Node_Id := Prefix (N); |
| S : constant Node_Id := Selector_Name (N); |
| T : Entity_Id := Etype (P); |
| I : Interp_Index; |
| I1 : Interp_Index := 0; -- prevent junk warning |
| It : Interp; |
| It1 : Interp; |
| Found : Boolean; |
| |
| function Init_Component return Boolean; |
| -- Check whether this is the initialization of a component within an |
| -- init proc (by assignment or call to another init proc). If true, |
| -- there is no need for a discriminant check. |
| |
| -------------------- |
| -- Init_Component -- |
| -------------------- |
| |
| function Init_Component return Boolean is |
| begin |
| return Inside_Init_Proc |
| and then Nkind (Prefix (N)) = N_Identifier |
| and then Chars (Prefix (N)) = Name_uInit |
| and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative; |
| end Init_Component; |
| |
| -- Start of processing for Resolve_Selected_Component |
| |
| begin |
| if Is_Overloaded (P) then |
| |
| -- Use the context type to select the prefix that has a selector |
| -- of the correct name and type. |
| |
| Found := False; |
| Get_First_Interp (P, I, It); |
| |
| Search : while Present (It.Typ) loop |
| if Is_Access_Type (It.Typ) then |
| T := Designated_Type (It.Typ); |
| else |
| T := It.Typ; |
| end if; |
| |
| -- Locate selected component. For a private prefix the selector |
| -- can denote a discriminant. |
| |
| if Is_Record_Type (T) or else Is_Private_Type (T) then |
| |
| -- The visible components of a class-wide type are those of |
| -- the root type. |
| |
| if Is_Class_Wide_Type (T) then |
| T := Etype (T); |
| end if; |
| |
| Comp := First_Entity (T); |
| while Present (Comp) loop |
| if Chars (Comp) = Chars (S) |
| and then Covers (Etype (Comp), Typ) |
| then |
| if not Found then |
| Found := True; |
| I1 := I; |
| It1 := It; |
| Comp1 := Comp; |
| |
| else |
| It := Disambiguate (P, I1, I, Any_Type); |
| |
| if It = No_Interp then |
| Error_Msg_N |
| ("ambiguous prefix for selected component", N); |
| Set_Etype (N, Typ); |
| return; |
| |
| else |
| It1 := It; |
| |
| -- There may be an implicit dereference. Retrieve |
| -- designated record type. |
| |
| if Is_Access_Type (It1.Typ) then |
| T := Designated_Type (It1.Typ); |
| else |
| T := It1.Typ; |
| end if; |
| |
| if Scope (Comp1) /= T then |
| |
| -- Resolution chooses the new interpretation. |
| -- Find the component with the right name. |
| |
| Comp1 := First_Entity (T); |
| while Present (Comp1) |
| and then Chars (Comp1) /= Chars (S) |
| loop |
| Comp1 := Next_Entity (Comp1); |
| end loop; |
| end if; |
| |
| exit Search; |
| end if; |
| end if; |
| end if; |
| |
| Comp := Next_Entity (Comp); |
| end loop; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop Search; |
| |
| Resolve (P, It1.Typ); |
| Set_Etype (N, Typ); |
| Set_Entity_With_Checks (S, Comp1); |
| |
| else |
| -- Resolve prefix with its type |
| |
| Resolve (P, T); |
| end if; |
| |
| -- Generate cross-reference. We needed to wait until full overloading |
| -- resolution was complete to do this, since otherwise we can't tell if |
| -- we are an lvalue or not. |
| |
| if May_Be_Lvalue (N) then |
| Generate_Reference (Entity (S), S, 'm'); |
| else |
| Generate_Reference (Entity (S), S, 'r'); |
| end if; |
| |
| -- If prefix is an access type, the node will be transformed into an |
| -- explicit dereference during expansion. The type of the node is the |
| -- designated type of that of the prefix. |
| |
| if Is_Access_Type (Etype (P)) then |
| T := Designated_Type (Etype (P)); |
| Check_Fully_Declared_Prefix (T, P); |
| else |
| T := Etype (P); |
| end if; |
| |
| -- Set flag for expander if discriminant check required |
| |
| if Has_Discriminants (T) |
| and then Ekind_In (Entity (S), E_Component, E_Discriminant) |
| and then Present (Original_Record_Component (Entity (S))) |
| and then Ekind (Original_Record_Component (Entity (S))) = E_Component |
| and then not Discriminant_Checks_Suppressed (T) |
| and then not Init_Component |
| then |
| Set_Do_Discriminant_Check (N); |
| end if; |
| |
| if Ekind (Entity (S)) = E_Void then |
| Error_Msg_N ("premature use of component", S); |
| end if; |
| |
| -- If the prefix is a record conversion, this may be a renamed |
| -- discriminant whose bounds differ from those of the original |
| -- one, so we must ensure that a range check is performed. |
| |
| if Nkind (P) = N_Type_Conversion |
| and then Ekind (Entity (S)) = E_Discriminant |
| and then Is_Discrete_Type (Typ) |
| then |
| Set_Etype (N, Base_Type (Typ)); |
| end if; |
| |
| -- Note: No Eval processing is required, because the prefix is of a |
| -- record type, or protected type, and neither can possibly be static. |
| |
| -- If the array type is atomic, and is packed, and we are in a left side |
| -- context, then this is worth a warning, since we have a situation |
| -- where the access to the component may cause extra read/writes of the |
| -- atomic array object, which could be considered unexpected. |
| |
| if Nkind (N) = N_Selected_Component |
| and then (Is_Atomic (T) |
| or else (Is_Entity_Name (Prefix (N)) |
| and then Is_Atomic (Entity (Prefix (N))))) |
| and then Is_Packed (T) |
| and then Is_LHS (N) = Yes |
| then |
| Error_Msg_N |
| ("??assignment to component of packed atomic record", Prefix (N)); |
| Error_Msg_N |
| ("\??may cause unexpected accesses to atomic object", Prefix (N)); |
| end if; |
| |
| Analyze_Dimension (N); |
| end Resolve_Selected_Component; |
| |
| ------------------- |
| -- Resolve_Shift -- |
| ------------------- |
| |
| procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| |
| begin |
| -- We do the resolution using the base type, because intermediate values |
| -- in expressions always are of the base type, not a subtype of it. |
| |
| Resolve (L, B_Typ); |
| Resolve (R, Standard_Natural); |
| |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (R); |
| |
| Set_Etype (N, B_Typ); |
| Generate_Operator_Reference (N, B_Typ); |
| Eval_Shift (N); |
| end Resolve_Shift; |
| |
| --------------------------- |
| -- Resolve_Short_Circuit -- |
| --------------------------- |
| |
| procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| |
| begin |
| -- Ensure all actions associated with the left operand (e.g. |
| -- finalization of transient controlled objects) are fully evaluated |
| -- locally within an expression with actions. This is particularly |
| -- helpful for coverage analysis. However this should not happen in |
| -- generics. |
| |
| if Expander_Active then |
| declare |
| Reloc_L : constant Node_Id := Relocate_Node (L); |
| begin |
| Save_Interps (Old_N => L, New_N => Reloc_L); |
| |
| Rewrite (L, |
| Make_Expression_With_Actions (Sloc (L), |
| Actions => New_List, |
| Expression => Reloc_L)); |
| |
| -- Set Comes_From_Source on L to preserve warnings for unset |
| -- reference. |
| |
| Set_Comes_From_Source (L, Comes_From_Source (Reloc_L)); |
| end; |
| end if; |
| |
| Resolve (L, B_Typ); |
| Resolve (R, B_Typ); |
| |
| -- Check for issuing warning for always False assert/check, this happens |
| -- when assertions are turned off, in which case the pragma Assert/Check |
| -- was transformed into: |
| |
| -- if False and then <condition> then ... |
| |
| -- and we detect this pattern |
| |
| if Warn_On_Assertion_Failure |
| and then Is_Entity_Name (R) |
| and then Entity (R) = Standard_False |
| and then Nkind (Parent (N)) = N_If_Statement |
| and then Nkind (N) = N_And_Then |
| and then Is_Entity_Name (L) |
| and then Entity (L) = Standard_False |
| then |
| declare |
| Orig : constant Node_Id := Original_Node (Parent (N)); |
| |
| begin |
| -- Special handling of Asssert pragma |
| |
| if Nkind (Orig) = N_Pragma |
| and then Pragma_Name (Orig) = Name_Assert |
| then |
| declare |
| Expr : constant Node_Id := |
| Original_Node |
| (Expression |
| (First (Pragma_Argument_Associations (Orig)))); |
| |
| begin |
| -- Don't warn if original condition is explicit False, |
| -- since obviously the failure is expected in this case. |
| |
| if Is_Entity_Name (Expr) |
| and then Entity (Expr) = Standard_False |
| then |
| null; |
| |
| -- Issue warning. We do not want the deletion of the |
| -- IF/AND-THEN to take this message with it. We achieve this |
| -- by making sure that the expanded code points to the Sloc |
| -- of the expression, not the original pragma. |
| |
| else |
| -- Note: Use Error_Msg_F here rather than Error_Msg_N. |
| -- The source location of the expression is not usually |
| -- the best choice here. For example, it gets located on |
| -- the last AND keyword in a chain of boolean expressiond |
| -- AND'ed together. It is best to put the message on the |
| -- first character of the assertion, which is the effect |
| -- of the First_Node call here. |
| |
| Error_Msg_F |
| ("?A?assertion would fail at run time!", |
| Expression |
| (First (Pragma_Argument_Associations (Orig)))); |
| end if; |
| end; |
| |
| -- Similar processing for Check pragma |
| |
| elsif Nkind (Orig) = N_Pragma |
| and then Pragma_Name (Orig) = Name_Check |
| then |
| -- Don't want to warn if original condition is explicit False |
| |
| declare |
| Expr : constant Node_Id := |
| Original_Node |
| (Expression |
| (Next (First (Pragma_Argument_Associations (Orig))))); |
| begin |
| if Is_Entity_Name (Expr) |
| and then Entity (Expr) = Standard_False |
| then |
| null; |
| |
| -- Post warning |
| |
| else |
| -- Again use Error_Msg_F rather than Error_Msg_N, see |
| -- comment above for an explanation of why we do this. |
| |
| Error_Msg_F |
| ("?A?check would fail at run time!", |
| Expression |
| (Last (Pragma_Argument_Associations (Orig)))); |
| end if; |
| end; |
| end if; |
| end; |
| end if; |
| |
| -- Continue with processing of short circuit |
| |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (R); |
| |
| Set_Etype (N, B_Typ); |
| Eval_Short_Circuit (N); |
| end Resolve_Short_Circuit; |
| |
| ------------------- |
| -- Resolve_Slice -- |
| ------------------- |
| |
| procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is |
| Drange : constant Node_Id := Discrete_Range (N); |
| Name : constant Node_Id := Prefix (N); |
| Array_Type : Entity_Id := Empty; |
| Dexpr : Node_Id := Empty; |
| Index_Type : Entity_Id; |
| |
| begin |
| if Is_Overloaded (Name) then |
| |
| -- Use the context type to select the prefix that yields the correct |
| -- array type. |
| |
| declare |
| I : Interp_Index; |
| I1 : Interp_Index := 0; |
| It : Interp; |
| P : constant Node_Id := Prefix (N); |
| Found : Boolean := False; |
| |
| begin |
| Get_First_Interp (P, I, It); |
| while Present (It.Typ) loop |
| if (Is_Array_Type (It.Typ) |
| and then Covers (Typ, It.Typ)) |
| or else (Is_Access_Type (It.Typ) |
| and then Is_Array_Type (Designated_Type (It.Typ)) |
| and then Covers (Typ, Designated_Type (It.Typ))) |
| then |
| if Found then |
| It := Disambiguate (P, I1, I, Any_Type); |
| |
| if It = No_Interp then |
| Error_Msg_N ("ambiguous prefix for slicing", N); |
| Set_Etype (N, Typ); |
| return; |
| else |
| Found := True; |
| Array_Type := It.Typ; |
| I1 := I; |
| end if; |
| else |
| Found := True; |
| Array_Type := It.Typ; |
| I1 := I; |
| end if; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end; |
| |
| else |
| Array_Type := Etype (Name); |
| end if; |
| |
| Resolve (Name, Array_Type); |
| |
| if Is_Access_Type (Array_Type) then |
| Apply_Access_Check (N); |
| Array_Type := Designated_Type (Array_Type); |
| |
| -- If the prefix is an access to an unconstrained array, we must use |
| -- the actual subtype of the object to perform the index checks. The |
| -- object denoted by the prefix is implicit in the node, so we build |
| -- an explicit representation for it in order to compute the actual |
| -- subtype. |
| |
| if not Is_Constrained (Array_Type) then |
| Remove_Side_Effects (Prefix (N)); |
| |
| declare |
| Obj : constant Node_Id := |
| Make_Explicit_Dereference (Sloc (N), |
| Prefix => New_Copy_Tree (Prefix (N))); |
| begin |
| Set_Etype (Obj, Array_Type); |
| Set_Parent (Obj, Parent (N)); |
| Array_Type := Get_Actual_Subtype (Obj); |
| end; |
| end if; |
| |
| elsif Is_Entity_Name (Name) |
| or else Nkind (Name) = N_Explicit_Dereference |
| or else (Nkind (Name) = N_Function_Call |
| and then not Is_Constrained (Etype (Name))) |
| then |
| Array_Type := Get_Actual_Subtype (Name); |
| |
| -- If the name is a selected component that depends on discriminants, |
| -- build an actual subtype for it. This can happen only when the name |
| -- itself is overloaded; otherwise the actual subtype is created when |
| -- the selected component is analyzed. |
| |
| elsif Nkind (Name) = N_Selected_Component |
| and then Full_Analysis |
| and then Depends_On_Discriminant (First_Index (Array_Type)) |
| then |
| declare |
| Act_Decl : constant Node_Id := |
| Build_Actual_Subtype_Of_Component (Array_Type, Name); |
| begin |
| Insert_Action (N, Act_Decl); |
| Array_Type := Defining_Identifier (Act_Decl); |
| end; |
| |
| -- Maybe this should just be "else", instead of checking for the |
| -- specific case of slice??? This is needed for the case where the |
| -- prefix is an Image attribute, which gets expanded to a slice, and so |
| -- has a constrained subtype which we want to use for the slice range |
| -- check applied below (the range check won't get done if the |
| -- unconstrained subtype of the 'Image is used). |
| |
| elsif Nkind (Name) = N_Slice then |
| Array_Type := Etype (Name); |
| end if; |
| |
| -- Obtain the type of the array index |
| |
| if Ekind (Array_Type) = E_String_Literal_Subtype then |
| Index_Type := Etype (String_Literal_Low_Bound (Array_Type)); |
| else |
| Index_Type := Etype (First_Index (Array_Type)); |
| end if; |
| |
| -- If name was overloaded, set slice type correctly now |
| |
| Set_Etype (N, Array_Type); |
| |
| -- Handle the generation of a range check that compares the array index |
| -- against the discrete_range. The check is not applied to internally |
| -- built nodes associated with the expansion of dispatch tables. Check |
| -- that Ada.Tags has already been loaded to avoid extra dependencies on |
| -- the unit. |
| |
| if Tagged_Type_Expansion |
| and then RTU_Loaded (Ada_Tags) |
| and then Nkind (Prefix (N)) = N_Selected_Component |
| and then Present (Entity (Selector_Name (Prefix (N)))) |
| and then Entity (Selector_Name (Prefix (N))) = |
| RTE_Record_Component (RE_Prims_Ptr) |
| then |
| null; |
| |
| -- The discrete_range is specified by a subtype indication. Create a |
| -- shallow copy and inherit the type, parent and source location from |
| -- the discrete_range. This ensures that the range check is inserted |
| -- relative to the slice and that the runtime exception points to the |
| -- proper construct. |
| |
| elsif Is_Entity_Name (Drange) then |
| Dexpr := New_Copy (Scalar_Range (Entity (Drange))); |
| |
| Set_Etype (Dexpr, Etype (Drange)); |
| Set_Parent (Dexpr, Parent (Drange)); |
| Set_Sloc (Dexpr, Sloc (Drange)); |
| |
| -- The discrete_range is a regular range. Resolve the bounds and remove |
| -- their side effects. |
| |
| else |
| Resolve (Drange, Base_Type (Index_Type)); |
| |
| if Nkind (Drange) = N_Range then |
| Force_Evaluation (Low_Bound (Drange)); |
| Force_Evaluation (High_Bound (Drange)); |
| |
| Dexpr := Drange; |
| end if; |
| end if; |
| |
| if Present (Dexpr) then |
| Apply_Range_Check (Dexpr, Index_Type); |
| end if; |
| |
| Set_Slice_Subtype (N); |
| |
| -- Check bad use of type with predicates |
| |
| if Has_Predicates (Etype (Drange)) then |
| Bad_Predicated_Subtype_Use |
| ("subtype& has predicate, not allowed in slice", |
| Drange, Etype (Drange)); |
| |
| -- Otherwise here is where we check suspicious indexes |
| |
| elsif Nkind (Drange) = N_Range then |
| Warn_On_Suspicious_Index (Name, Low_Bound (Drange)); |
| Warn_On_Suspicious_Index (Name, High_Bound (Drange)); |
| end if; |
| |
| Analyze_Dimension (N); |
| Eval_Slice (N); |
| end Resolve_Slice; |
| |
| ---------------------------- |
| -- Resolve_String_Literal -- |
| ---------------------------- |
| |
| procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is |
| C_Typ : constant Entity_Id := Component_Type (Typ); |
| R_Typ : constant Entity_Id := Root_Type (C_Typ); |
| Loc : constant Source_Ptr := Sloc (N); |
| Str : constant String_Id := Strval (N); |
| Strlen : constant Nat := String_Length (Str); |
| Subtype_Id : Entity_Id; |
| Need_Check : Boolean; |
| |
| begin |
| -- For a string appearing in a concatenation, defer creation of the |
| -- string_literal_subtype until the end of the resolution of the |
| -- concatenation, because the literal may be constant-folded away. This |
| -- is a useful optimization for long concatenation expressions. |
| |
| -- If the string is an aggregate built for a single character (which |
| -- happens in a non-static context) or a is null string to which special |
| -- checks may apply, we build the subtype. Wide strings must also get a |
| -- string subtype if they come from a one character aggregate. Strings |
| -- generated by attributes might be static, but it is often hard to |
| -- determine whether the enclosing context is static, so we generate |
| -- subtypes for them as well, thus losing some rarer optimizations ??? |
| -- Same for strings that come from a static conversion. |
| |
| Need_Check := |
| (Strlen = 0 and then Typ /= Standard_String) |
| or else Nkind (Parent (N)) /= N_Op_Concat |
| or else (N /= Left_Opnd (Parent (N)) |
| and then N /= Right_Opnd (Parent (N))) |
| or else ((Typ = Standard_Wide_String |
| or else Typ = Standard_Wide_Wide_String) |
| and then Nkind (Original_Node (N)) /= N_String_Literal); |
| |
| -- If the resolving type is itself a string literal subtype, we can just |
| -- reuse it, since there is no point in creating another. |
| |
| if Ekind (Typ) = E_String_Literal_Subtype then |
| Subtype_Id := Typ; |
| |
| elsif Nkind (Parent (N)) = N_Op_Concat |
| and then not Need_Check |
| and then not Nkind_In (Original_Node (N), N_Character_Literal, |
| N_Attribute_Reference, |
| N_Qualified_Expression, |
| N_Type_Conversion) |
| then |
| Subtype_Id := Typ; |
| |
| -- Otherwise we must create a string literal subtype. Note that the |
| -- whole idea of string literal subtypes is simply to avoid the need |
| -- for building a full fledged array subtype for each literal. |
| |
| else |
| Set_String_Literal_Subtype (N, Typ); |
| Subtype_Id := Etype (N); |
| end if; |
| |
| if Nkind (Parent (N)) /= N_Op_Concat |
| or else Need_Check |
| then |
| Set_Etype (N, Subtype_Id); |
| Eval_String_Literal (N); |
| end if; |
| |
| if Is_Limited_Composite (Typ) |
| or else Is_Private_Composite (Typ) |
| then |
| Error_Msg_N ("string literal not available for private array", N); |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| -- The validity of a null string has been checked in the call to |
| -- Eval_String_Literal. |
| |
| if Strlen = 0 then |
| return; |
| |
| -- Always accept string literal with component type Any_Character, which |
| -- occurs in error situations and in comparisons of literals, both of |
| -- which should accept all literals. |
| |
| elsif R_Typ = Any_Character then |
| return; |
| |
| -- If the type is bit-packed, then we always transform the string |
| -- literal into a full fledged aggregate. |
| |
| elsif Is_Bit_Packed_Array (Typ) then |
| null; |
| |
| -- Deal with cases of Wide_Wide_String, Wide_String, and String |
| |
| else |
| -- For Standard.Wide_Wide_String, or any other type whose component |
| -- type is Standard.Wide_Wide_Character, we know that all the |
| -- characters in the string must be acceptable, since the parser |
| -- accepted the characters as valid character literals. |
| |
| if R_Typ = Standard_Wide_Wide_Character then |
| null; |
| |
| -- For the case of Standard.String, or any other type whose component |
| -- type is Standard.Character, we must make sure that there are no |
| -- wide characters in the string, i.e. that it is entirely composed |
| -- of characters in range of type Character. |
| |
| -- If the string literal is the result of a static concatenation, the |
| -- test has already been performed on the components, and need not be |
| -- repeated. |
| |
| elsif R_Typ = Standard_Character |
| and then Nkind (Original_Node (N)) /= N_Op_Concat |
| then |
| for J in 1 .. Strlen loop |
| if not In_Character_Range (Get_String_Char (Str, J)) then |
| |
| -- If we are out of range, post error. This is one of the |
| -- very few places that we place the flag in the middle of |
| -- a token, right under the offending wide character. Not |
| -- quite clear if this is right wrt wide character encoding |
| -- sequences, but it's only an error message. |
| |
| Error_Msg |
| ("literal out of range of type Standard.Character", |
| Source_Ptr (Int (Loc) + J)); |
| return; |
| end if; |
| end loop; |
| |
| -- For the case of Standard.Wide_String, or any other type whose |
| -- component type is Standard.Wide_Character, we must make sure that |
| -- there are no wide characters in the string, i.e. that it is |
| -- entirely composed of characters in range of type Wide_Character. |
| |
| -- If the string literal is the result of a static concatenation, |
| -- the test has already been performed on the components, and need |
| -- not be repeated. |
| |
| elsif R_Typ = Standard_Wide_Character |
| and then Nkind (Original_Node (N)) /= N_Op_Concat |
| then |
| for J in 1 .. Strlen loop |
| if not In_Wide_Character_Range (Get_String_Char (Str, J)) then |
| |
| -- If we are out of range, post error. This is one of the |
| -- very few places that we place the flag in the middle of |
| -- a token, right under the offending wide character. |
| |
| -- This is not quite right, because characters in general |
| -- will take more than one character position ??? |
| |
| Error_Msg |
| ("literal out of range of type Standard.Wide_Character", |
| Source_Ptr (Int (Loc) + J)); |
| return; |
| end if; |
| end loop; |
| |
| -- If the root type is not a standard character, then we will convert |
| -- the string into an aggregate and will let the aggregate code do |
| -- the checking. Standard Wide_Wide_Character is also OK here. |
| |
| else |
| null; |
| end if; |
| |
| -- See if the component type of the array corresponding to the string |
| -- has compile time known bounds. If yes we can directly check |
| -- whether the evaluation of the string will raise constraint error. |
| -- Otherwise we need to transform the string literal into the |
| -- corresponding character aggregate and let the aggregate code do |
| -- the checking. |
| |
| if Is_Standard_Character_Type (R_Typ) then |
| |
| -- Check for the case of full range, where we are definitely OK |
| |
| if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then |
| return; |
| end if; |
| |
| -- Here the range is not the complete base type range, so check |
| |
| declare |
| Comp_Typ_Lo : constant Node_Id := |
| Type_Low_Bound (Component_Type (Typ)); |
| Comp_Typ_Hi : constant Node_Id := |
| Type_High_Bound (Component_Type (Typ)); |
| |
| Char_Val : Uint; |
| |
| begin |
| if Compile_Time_Known_Value (Comp_Typ_Lo) |
| and then Compile_Time_Known_Value (Comp_Typ_Hi) |
| then |
| for J in 1 .. Strlen loop |
| Char_Val := UI_From_Int (Int (Get_String_Char (Str, J))); |
| |
| if Char_Val < Expr_Value (Comp_Typ_Lo) |
| or else Char_Val > Expr_Value (Comp_Typ_Hi) |
| then |
| Apply_Compile_Time_Constraint_Error |
| (N, "character out of range??", |
| CE_Range_Check_Failed, |
| Loc => Source_Ptr (Int (Loc) + J)); |
| end if; |
| end loop; |
| |
| return; |
| end if; |
| end; |
| end if; |
| end if; |
| |
| -- If we got here we meed to transform the string literal into the |
| -- equivalent qualified positional array aggregate. This is rather |
| -- heavy artillery for this situation, but it is hard work to avoid. |
| |
| declare |
| Lits : constant List_Id := New_List; |
| P : Source_Ptr := Loc + 1; |
| C : Char_Code; |
| |
| begin |
| -- Build the character literals, we give them source locations that |
| -- correspond to the string positions, which is a bit tricky given |
| -- the possible presence of wide character escape sequences. |
| |
| for J in 1 .. Strlen loop |
| C := Get_String_Char (Str, J); |
| Set_Character_Literal_Name (C); |
| |
| Append_To (Lits, |
| Make_Character_Literal (P, |
| Chars => Name_Find, |
| Char_Literal_Value => UI_From_CC (C))); |
| |
| if In_Character_Range (C) then |
| P := P + 1; |
| |
| -- Should we have a call to Skip_Wide here ??? |
| |
| -- ??? else |
| -- Skip_Wide (P); |
| |
| end if; |
| end loop; |
| |
| Rewrite (N, |
| Make_Qualified_Expression (Loc, |
| Subtype_Mark => New_Occurrence_Of (Typ, Loc), |
| Expression => |
| Make_Aggregate (Loc, Expressions => Lits))); |
| |
| Analyze_And_Resolve (N, Typ); |
| end; |
| end Resolve_String_Literal; |
| |
| ----------------------------- |
| -- Resolve_Type_Conversion -- |
| ----------------------------- |
| |
| procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is |
| Conv_OK : constant Boolean := Conversion_OK (N); |
| Operand : constant Node_Id := Expression (N); |
| Operand_Typ : constant Entity_Id := Etype (Operand); |
| Target_Typ : constant Entity_Id := Etype (N); |
| Rop : Node_Id; |
| Orig_N : Node_Id; |
| Orig_T : Node_Id; |
| |
| Test_Redundant : Boolean := Warn_On_Redundant_Constructs; |
| -- Set to False to suppress cases where we want to suppress the test |
| -- for redundancy to avoid possible false positives on this warning. |
| |
| begin |
| if not Conv_OK |
| and then not Valid_Conversion (N, Target_Typ, Operand) |
| then |
| return; |
| end if; |
| |
| -- If the Operand Etype is Universal_Fixed, then the conversion is |
| -- never redundant. We need this check because by the time we have |
| -- finished the rather complex transformation, the conversion looks |
| -- redundant when it is not. |
| |
| if Operand_Typ = Universal_Fixed then |
| Test_Redundant := False; |
| |
| -- If the operand is marked as Any_Fixed, then special processing is |
| -- required. This is also a case where we suppress the test for a |
| -- redundant conversion, since most certainly it is not redundant. |
| |
| elsif Operand_Typ = Any_Fixed then |
| Test_Redundant := False; |
| |
| -- Mixed-mode operation involving a literal. Context must be a fixed |
| -- type which is applied to the literal subsequently. |
| |
| if Is_Fixed_Point_Type (Typ) then |
| Set_Etype (Operand, Universal_Real); |
| |
| elsif Is_Numeric_Type (Typ) |
| and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide) |
| and then (Etype (Right_Opnd (Operand)) = Universal_Real |
| or else |
| Etype (Left_Opnd (Operand)) = Universal_Real) |
| then |
| -- Return if expression is ambiguous |
| |
| if Unique_Fixed_Point_Type (N) = Any_Type then |
| return; |
| |
| -- If nothing else, the available fixed type is Duration |
| |
| else |
| Set_Etype (Operand, Standard_Duration); |
| end if; |
| |
| -- Resolve the real operand with largest available precision |
| |
| if Etype (Right_Opnd (Operand)) = Universal_Real then |
| Rop := New_Copy_Tree (Right_Opnd (Operand)); |
| else |
| Rop := New_Copy_Tree (Left_Opnd (Operand)); |
| end if; |
| |
| Resolve (Rop, Universal_Real); |
| |
| -- If the operand is a literal (it could be a non-static and |
| -- illegal exponentiation) check whether the use of Duration |
| -- is potentially inaccurate. |
| |
| if Nkind (Rop) = N_Real_Literal |
| and then Realval (Rop) /= Ureal_0 |
| and then abs (Realval (Rop)) < Delta_Value (Standard_Duration) |
| then |
| Error_Msg_N |
| ("??universal real operand can only " |
| & "be interpreted as Duration!", Rop); |
| Error_Msg_N |
| ("\??precision will be lost in the conversion!", Rop); |
| end if; |
| |
| elsif Is_Numeric_Type (Typ) |
| and then Nkind (Operand) in N_Op |
| and then Unique_Fixed_Point_Type (N) /= Any_Type |
| then |
| Set_Etype (Operand, Standard_Duration); |
| |
| else |
| Error_Msg_N ("invalid context for mixed mode operation", N); |
| Set_Etype (Operand, Any_Type); |
| return; |
| end if; |
| end if; |
| |
| Resolve (Operand); |
| |
| -- In SPARK, a type conversion between array types should be restricted |
| -- to types which have matching static bounds. |
| |
| -- Protect call to Matching_Static_Array_Bounds to avoid costly |
| -- operation if not needed. |
| |
| if Restriction_Check_Required (SPARK_05) |
| and then Is_Array_Type (Target_Typ) |
| and then Is_Array_Type (Operand_Typ) |
| and then Operand_Typ /= Any_Composite -- or else Operand in error |
| and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ) |
| then |
| Check_SPARK_Restriction |
| ("array types should have matching static bounds", N); |
| end if; |
| |
| -- In formal mode, the operand of an ancestor type conversion must be an |
| -- object (not an expression). |
| |
| if Is_Tagged_Type (Target_Typ) |
| and then not Is_Class_Wide_Type (Target_Typ) |
| and then Is_Tagged_Type (Operand_Typ) |
| and then not Is_Class_Wide_Type (Operand_Typ) |
| and then Is_Ancestor (Target_Typ, Operand_Typ) |
| and then not Is_SPARK_Object_Reference (Operand) |
| then |
| Check_SPARK_Restriction ("object required", Operand); |
| end if; |
| |
| Analyze_Dimension (N); |
| |
| -- Note: we do the Eval_Type_Conversion call before applying the |
| -- required checks for a subtype conversion. This is important, since |
| -- both are prepared under certain circumstances to change the type |
| -- conversion to a constraint error node, but in the case of |
| -- Eval_Type_Conversion this may reflect an illegality in the static |
| -- case, and we would miss the illegality (getting only a warning |
| -- message), if we applied the type conversion checks first. |
| |
| Eval_Type_Conversion (N); |
| |
| -- Even when evaluation is not possible, we may be able to simplify the |
| -- conversion or its expression. This needs to be done before applying |
| -- checks, since otherwise the checks may use the original expression |
| -- and defeat the simplifications. This is specifically the case for |
| -- elimination of the floating-point Truncation attribute in |
| -- float-to-int conversions. |
| |
| Simplify_Type_Conversion (N); |
| |
| -- If after evaluation we still have a type conversion, then we may need |
| -- to apply checks required for a subtype conversion. |
| |
| -- Skip these type conversion checks if universal fixed operands |
| -- operands involved, since range checks are handled separately for |
| -- these cases (in the appropriate Expand routines in unit Exp_Fixd). |
| |
| if Nkind (N) = N_Type_Conversion |
| and then not Is_Generic_Type (Root_Type (Target_Typ)) |
| and then Target_Typ /= Universal_Fixed |
| and then Operand_Typ /= Universal_Fixed |
| then |
| Apply_Type_Conversion_Checks (N); |
| end if; |
| |
| -- Issue warning for conversion of simple object to its own type. We |
| -- have to test the original nodes, since they may have been rewritten |
| -- by various optimizations. |
| |
| Orig_N := Original_Node (N); |
| |
| -- Here we test for a redundant conversion if the warning mode is |
| -- active (and was not locally reset), and we have a type conversion |
| -- from source not appearing in a generic instance. |
| |
| if Test_Redundant |
| and then Nkind (Orig_N) = N_Type_Conversion |
| and then Comes_From_Source (Orig_N) |
| and then not In_Instance |
| then |
| Orig_N := Original_Node (Expression (Orig_N)); |
| Orig_T := Target_Typ; |
| |
| -- If the node is part of a larger expression, the Target_Type |
| -- may not be the original type of the node if the context is a |
| -- condition. Recover original type to see if conversion is needed. |
| |
| if Is_Boolean_Type (Orig_T) |
| and then Nkind (Parent (N)) in N_Op |
| then |
| Orig_T := Etype (Parent (N)); |
| end if; |
| |
| -- If we have an entity name, then give the warning if the entity |
| -- is the right type, or if it is a loop parameter covered by the |
| -- original type (that's needed because loop parameters have an |
| -- odd subtype coming from the bounds). |
| |
| if (Is_Entity_Name (Orig_N) |
| and then |
| (Etype (Entity (Orig_N)) = Orig_T |
| or else |
| (Ekind (Entity (Orig_N)) = E_Loop_Parameter |
| and then Covers (Orig_T, Etype (Entity (Orig_N)))))) |
| |
| -- If not an entity, then type of expression must match |
| |
| or else Etype (Orig_N) = Orig_T |
| then |
| -- One more check, do not give warning if the analyzed conversion |
| -- has an expression with non-static bounds, and the bounds of the |
| -- target are static. This avoids junk warnings in cases where the |
| -- conversion is necessary to establish staticness, for example in |
| -- a case statement. |
| |
| if not Is_OK_Static_Subtype (Operand_Typ) |
| and then Is_OK_Static_Subtype (Target_Typ) |
| then |
| null; |
| |
| -- Finally, if this type conversion occurs in a context requiring |
| -- a prefix, and the expression is a qualified expression then the |
| -- type conversion is not redundant, since a qualified expression |
| -- is not a prefix, whereas a type conversion is. For example, "X |
| -- := T'(Funx(...)).Y;" is illegal because a selected component |
| -- requires a prefix, but a type conversion makes it legal: "X := |
| -- T(T'(Funx(...))).Y;" |
| |
| -- In Ada 2012, a qualified expression is a name, so this idiom is |
| -- no longer needed, but we still suppress the warning because it |
| -- seems unfriendly for warnings to pop up when you switch to the |
| -- newer language version. |
| |
| elsif Nkind (Orig_N) = N_Qualified_Expression |
| and then Nkind_In (Parent (N), N_Attribute_Reference, |
| N_Indexed_Component, |
| N_Selected_Component, |
| N_Slice, |
| N_Explicit_Dereference) |
| then |
| null; |
| |
| -- Never warn on conversion to Long_Long_Integer'Base since |
| -- that is most likely an artifact of the extended overflow |
| -- checking and comes from complex expanded code. |
| |
| elsif Orig_T = Base_Type (Standard_Long_Long_Integer) then |
| null; |
| |
| -- Here we give the redundant conversion warning. If it is an |
| -- entity, give the name of the entity in the message. If not, |
| -- just mention the expression. |
| |
| -- Shoudn't we test Warn_On_Redundant_Constructs here ??? |
| |
| else |
| if Is_Entity_Name (Orig_N) then |
| Error_Msg_Node_2 := Orig_T; |
| Error_Msg_NE -- CODEFIX |
| ("??redundant conversion, & is of type &!", |
| N, Entity (Orig_N)); |
| else |
| Error_Msg_NE |
| ("??redundant conversion, expression is of type&!", |
| N, Orig_T); |
| end if; |
| end if; |
| end if; |
| end if; |
| |
| -- Ada 2005 (AI-251): Handle class-wide interface type conversions. |
| -- No need to perform any interface conversion if the type of the |
| -- expression coincides with the target type. |
| |
| if Ada_Version >= Ada_2005 |
| and then Expander_Active |
| and then Operand_Typ /= Target_Typ |
| then |
| declare |
| Opnd : Entity_Id := Operand_Typ; |
| Target : Entity_Id := Target_Typ; |
| |
| begin |
| if Is_Access_Type (Opnd) then |
| Opnd := Designated_Type (Opnd); |
| end if; |
| |
| if Is_Access_Type (Target_Typ) then |
| Target := Designated_Type (Target); |
| end if; |
| |
| if Opnd = Target then |
| null; |
| |
| -- Conversion from interface type |
| |
| elsif Is_Interface (Opnd) then |
| |
| -- Ada 2005 (AI-217): Handle entities from limited views |
| |
| if From_Limited_With (Opnd) then |
| Error_Msg_Qual_Level := 99; |
| Error_Msg_NE -- CODEFIX |
| ("missing WITH clause on package &", N, |
| Cunit_Entity (Get_Source_Unit (Base_Type (Opnd)))); |
| Error_Msg_N |
| ("type conversions require visibility of the full view", |
| N); |
| |
| elsif From_Limited_With (Target) |
| and then not |
| (Is_Access_Type (Target_Typ) |
| and then Present (Non_Limited_View (Etype (Target)))) |
| then |
| Error_Msg_Qual_Level := 99; |
| Error_Msg_NE -- CODEFIX |
| ("missing WITH clause on package &", N, |
| Cunit_Entity (Get_Source_Unit (Base_Type (Target)))); |
| Error_Msg_N |
| ("type conversions require visibility of the full view", |
| N); |
| |
| else |
| Expand_Interface_Conversion (N); |
| end if; |
| |
| -- Conversion to interface type |
| |
| elsif Is_Interface (Target) then |
| |
| -- Handle subtypes |
| |
| if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then |
| Opnd := Etype (Opnd); |
| end if; |
| |
| if Is_Class_Wide_Type (Opnd) |
| or else Interface_Present_In_Ancestor |
| (Typ => Opnd, |
| Iface => Target) |
| then |
| Expand_Interface_Conversion (N); |
| else |
| Error_Msg_Name_1 := Chars (Etype (Target)); |
| Error_Msg_Name_2 := Chars (Opnd); |
| Error_Msg_N |
| ("wrong interface conversion (% is not a progenitor " |
| & "of %)", N); |
| end if; |
| end if; |
| end; |
| end if; |
| |
| -- Ada 2012: if target type has predicates, the result requires a |
| -- predicate check. If the context is a call to another predicate |
| -- check we must prevent infinite recursion. |
| |
| if Has_Predicates (Target_Typ) then |
| if Nkind (Parent (N)) = N_Function_Call |
| and then Present (Name (Parent (N))) |
| and then (Is_Predicate_Function (Entity (Name (Parent (N)))) |
| or else |
| Is_Predicate_Function_M (Entity (Name (Parent (N))))) |
| then |
| null; |
| |
| else |
| Apply_Predicate_Check (N, Target_Typ); |
| end if; |
| end if; |
| end Resolve_Type_Conversion; |
| |
| ---------------------- |
| -- Resolve_Unary_Op -- |
| ---------------------- |
| |
| procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| R : constant Node_Id := Right_Opnd (N); |
| OK : Boolean; |
| Lo : Uint; |
| Hi : Uint; |
| |
| begin |
| if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then |
| Error_Msg_Name_1 := Chars (Typ); |
| Check_SPARK_Restriction |
| ("unary operator not defined for modular type%", N); |
| end if; |
| |
| -- Deal with intrinsic unary operators |
| |
| if Comes_From_Source (N) |
| and then Ekind (Entity (N)) = E_Function |
| and then Is_Imported (Entity (N)) |
| and then Is_Intrinsic_Subprogram (Entity (N)) |
| then |
| Resolve_Intrinsic_Unary_Operator (N, Typ); |
| return; |
| end if; |
| |
| -- Deal with universal cases |
| |
| if Etype (R) = Universal_Integer |
| or else |
| Etype (R) = Universal_Real |
| then |
| Check_For_Visible_Operator (N, B_Typ); |
| end if; |
| |
| Set_Etype (N, B_Typ); |
| Resolve (R, B_Typ); |
| |
| -- Generate warning for expressions like abs (x mod 2) |
| |
| if Warn_On_Redundant_Constructs |
| and then Nkind (N) = N_Op_Abs |
| then |
| Determine_Range (Right_Opnd (N), OK, Lo, Hi); |
| |
| if OK and then Hi >= Lo and then Lo >= 0 then |
| Error_Msg_N -- CODEFIX |
| ("?r?abs applied to known non-negative value has no effect", N); |
| end if; |
| end if; |
| |
| -- Deal with reference generation |
| |
| Check_Unset_Reference (R); |
| Generate_Operator_Reference (N, B_Typ); |
| Analyze_Dimension (N); |
| Eval_Unary_Op (N); |
| |
| -- Set overflow checking bit. Much cleverer code needed here eventually |
| -- and perhaps the Resolve routines should be separated for the various |
| -- arithmetic operations, since they will need different processing ??? |
| |
| if Nkind (N) in N_Op then |
| if not Overflow_Checks_Suppressed (Etype (N)) then |
| Enable_Overflow_Check (N); |
| end if; |
| end if; |
| |
| -- Generate warning for expressions like -5 mod 3 for integers. No need |
| -- to worry in the floating-point case, since parens do not affect the |
| -- result so there is no point in giving in a warning. |
| |
| declare |
| Norig : constant Node_Id := Original_Node (N); |
| Rorig : Node_Id; |
| Val : Uint; |
| HB : Uint; |
| LB : Uint; |
| Lval : Uint; |
| Opnd : Node_Id; |
| |
| begin |
| if Warn_On_Questionable_Missing_Parens |
| and then Comes_From_Source (Norig) |
| and then Is_Integer_Type (Typ) |
| and then Nkind (Norig) = N_Op_Minus |
| then |
| Rorig := Original_Node (Right_Opnd (Norig)); |
| |
| -- We are looking for cases where the right operand is not |
| -- parenthesized, and is a binary operator, multiply, divide, or |
| -- mod. These are the cases where the grouping can affect results. |
| |
| if Paren_Count (Rorig) = 0 |
| and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide) |
| then |
| -- For mod, we always give the warning, since the value is |
| -- affected by the parenthesization (e.g. (-5) mod 315 /= |
| -- -(5 mod 315)). But for the other cases, the only concern is |
| -- overflow, e.g. for the case of 8 big signed (-(2 * 64) |
| -- overflows, but (-2) * 64 does not). So we try to give the |
| -- message only when overflow is possible. |
| |
| if Nkind (Rorig) /= N_Op_Mod |
| and then Compile_Time_Known_Value (R) |
| then |
| Val := Expr_Value (R); |
| |
| if Compile_Time_Known_Value (Type_High_Bound (Typ)) then |
| HB := Expr_Value (Type_High_Bound (Typ)); |
| else |
| HB := Expr_Value (Type_High_Bound (Base_Type (Typ))); |
| end if; |
| |
| if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then |
| LB := Expr_Value (Type_Low_Bound (Typ)); |
| else |
| LB := Expr_Value (Type_Low_Bound (Base_Type (Typ))); |
| end if; |
| |
| -- Note that the test below is deliberately excluding the |
| -- largest negative number, since that is a potentially |
| -- troublesome case (e.g. -2 * x, where the result is the |
| -- largest negative integer has an overflow with 2 * x). |
| |
| if Val > LB and then Val <= HB then |
| return; |
| end if; |
| end if; |
| |
| -- For the multiplication case, the only case we have to worry |
| -- about is when (-a)*b is exactly the largest negative number |
| -- so that -(a*b) can cause overflow. This can only happen if |
| -- a is a power of 2, and more generally if any operand is a |
| -- constant that is not a power of 2, then the parentheses |
| -- cannot affect whether overflow occurs. We only bother to |
| -- test the left most operand |
| |
| -- Loop looking at left operands for one that has known value |
| |
| Opnd := Rorig; |
| Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop |
| if Compile_Time_Known_Value (Left_Opnd (Opnd)) then |
| Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd))); |
| |
| -- Operand value of 0 or 1 skips warning |
| |
| if Lval <= 1 then |
| return; |
| |
| -- Otherwise check power of 2, if power of 2, warn, if |
| -- anything else, skip warning. |
| |
| else |
| while Lval /= 2 loop |
| if Lval mod 2 = 1 then |
| return; |
| else |
| Lval := Lval / 2; |
| end if; |
| end loop; |
| |
| exit Opnd_Loop; |
| end if; |
| end if; |
| |
| -- Keep looking at left operands |
| |
| Opnd := Left_Opnd (Opnd); |
| end loop Opnd_Loop; |
| |
| -- For rem or "/" we can only have a problematic situation |
| -- if the divisor has a value of minus one or one. Otherwise |
| -- overflow is impossible (divisor > 1) or we have a case of |
| -- division by zero in any case. |
| |
| if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem) |
| and then Compile_Time_Known_Value (Right_Opnd (Rorig)) |
| and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1 |
| then |
| return; |
| end if; |
| |
| -- If we fall through warning should be issued |
| |
| -- Shouldn't we test Warn_On_Questionable_Missing_Parens ??? |
| |
| Error_Msg_N |
| ("??unary minus expression should be parenthesized here!", N); |
| end if; |
| end if; |
| end; |
| end Resolve_Unary_Op; |
| |
| ---------------------------------- |
| -- Resolve_Unchecked_Expression -- |
| ---------------------------------- |
| |
| procedure Resolve_Unchecked_Expression |
| (N : Node_Id; |
| Typ : Entity_Id) |
| is |
| begin |
| Resolve (Expression (N), Typ, Suppress => All_Checks); |
| Set_Etype (N, Typ); |
| end Resolve_Unchecked_Expression; |
| |
| --------------------------------------- |
| -- Resolve_Unchecked_Type_Conversion -- |
| --------------------------------------- |
| |
| procedure Resolve_Unchecked_Type_Conversion |
| (N : Node_Id; |
| Typ : Entity_Id) |
| is |
| pragma Warnings (Off, Typ); |
| |
| Operand : constant Node_Id := Expression (N); |
| Opnd_Type : constant Entity_Id := Etype (Operand); |
| |
| begin |
| -- Resolve operand using its own type |
| |
| Resolve (Operand, Opnd_Type); |
| Analyze_Dimension (N); |
| Eval_Unchecked_Conversion (N); |
| end Resolve_Unchecked_Type_Conversion; |
| |
| ------------------------------ |
| -- Rewrite_Operator_As_Call -- |
| ------------------------------ |
| |
| procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Actuals : constant List_Id := New_List; |
| New_N : Node_Id; |
| |
| begin |
| if Nkind (N) in N_Binary_Op then |
| Append (Left_Opnd (N), Actuals); |
| end if; |
| |
| Append (Right_Opnd (N), Actuals); |
| |
| New_N := |
| Make_Function_Call (Sloc => Loc, |
| Name => New_Occurrence_Of (Nam, Loc), |
| Parameter_Associations => Actuals); |
| |
| Preserve_Comes_From_Source (New_N, N); |
| Preserve_Comes_From_Source (Name (New_N), N); |
| Rewrite (N, New_N); |
| Set_Etype (N, Etype (Nam)); |
| end Rewrite_Operator_As_Call; |
| |
| ------------------------------ |
| -- Rewrite_Renamed_Operator -- |
| ------------------------------ |
| |
| procedure Rewrite_Renamed_Operator |
| (N : Node_Id; |
| Op : Entity_Id; |
| Typ : Entity_Id) |
| is |
| Nam : constant Name_Id := Chars (Op); |
| Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op; |
| Op_Node : Node_Id; |
| |
| begin |
| -- Do not perform this transformation within a pre/postcondition, |
| -- because the expression will be re-analyzed, and the transformation |
| -- might affect the visibility of the operator, e.g. in an instance. |
| |
| if In_Assertion_Expr > 0 then |
| return; |
| end if; |
| |
| -- Rewrite the operator node using the real operator, not its renaming. |
| -- Exclude user-defined intrinsic operations of the same name, which are |
| -- treated separately and rewritten as calls. |
| |
| if Ekind (Op) /= E_Function or else Chars (N) /= Nam then |
| Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N)); |
| Set_Chars (Op_Node, Nam); |
| Set_Etype (Op_Node, Etype (N)); |
| Set_Entity (Op_Node, Op); |
| Set_Right_Opnd (Op_Node, Right_Opnd (N)); |
| |
| -- Indicate that both the original entity and its renaming are |
| -- referenced at this point. |
| |
| Generate_Reference (Entity (N), N); |
| Generate_Reference (Op, N); |
| |
| if Is_Binary then |
| Set_Left_Opnd (Op_Node, Left_Opnd (N)); |
| end if; |
| |
| Rewrite (N, Op_Node); |
| |
| -- If the context type is private, add the appropriate conversions so |
| -- that the operator is applied to the full view. This is done in the |
| -- routines that resolve intrinsic operators. |
| |
| if Is_Intrinsic_Subprogram (Op) |
| and then Is_Private_Type (Typ) |
| then |
| case Nkind (N) is |
| when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide | |
| N_Op_Expon | N_Op_Mod | N_Op_Rem => |
| Resolve_Intrinsic_Operator (N, Typ); |
| |
| when N_Op_Plus | N_Op_Minus | N_Op_Abs => |
| Resolve_Intrinsic_Unary_Operator (N, Typ); |
| |
| when others => |
| Resolve (N, Typ); |
| end case; |
| end if; |
| |
| elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then |
| |
| -- Operator renames a user-defined operator of the same name. Use the |
| -- original operator in the node, which is the one Gigi knows about. |
| |
| Set_Entity (N, Op); |
| Set_Is_Overloaded (N, False); |
| end if; |
| end Rewrite_Renamed_Operator; |
| |
| ----------------------- |
| -- Set_Slice_Subtype -- |
| ----------------------- |
| |
| -- Build an implicit subtype declaration to represent the type delivered by |
| -- the slice. This is an abbreviated version of an array subtype. We define |
| -- an index subtype for the slice, using either the subtype name or the |
| -- discrete range of the slice. To be consistent with index usage elsewhere |
| -- we create a list header to hold the single index. This list is not |
| -- otherwise attached to the syntax tree. |
| |
| procedure Set_Slice_Subtype (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Index_List : constant List_Id := New_List; |
| Index : Node_Id; |
| Index_Subtype : Entity_Id; |
| Index_Type : Entity_Id; |
| Slice_Subtype : Entity_Id; |
| Drange : constant Node_Id := Discrete_Range (N); |
| |
| begin |
| Index_Type := Base_Type (Etype (Drange)); |
| |
| if Is_Entity_Name (Drange) then |
| Index_Subtype := Entity (Drange); |
| |
| else |
| -- We force the evaluation of a range. This is definitely needed in |
| -- the renamed case, and seems safer to do unconditionally. Note in |
| -- any case that since we will create and insert an Itype referring |
| -- to this range, we must make sure any side effect removal actions |
| -- are inserted before the Itype definition. |
| |
| if Nkind (Drange) = N_Range then |
| Force_Evaluation (Low_Bound (Drange)); |
| Force_Evaluation (High_Bound (Drange)); |
| |
| -- If the discrete range is given by a subtype indication, the |
| -- type of the slice is the base of the subtype mark. |
| |
| elsif Nkind (Drange) = N_Subtype_Indication then |
| declare |
| R : constant Node_Id := Range_Expression (Constraint (Drange)); |
| begin |
| Index_Type := Base_Type (Entity (Subtype_Mark (Drange))); |
| Force_Evaluation (Low_Bound (R)); |
| Force_Evaluation (High_Bound (R)); |
| end; |
| end if; |
| |
| Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N); |
| |
| -- Take a new copy of Drange (where bounds have been rewritten to |
| -- reference side-effect-free names). Using a separate tree ensures |
| -- that further expansion (e.g. while rewriting a slice assignment |
| -- into a FOR loop) does not attempt to remove side effects on the |
| -- bounds again (which would cause the bounds in the index subtype |
| -- definition to refer to temporaries before they are defined) (the |
| -- reason is that some names are considered side effect free here |
| -- for the subtype, but not in the context of a loop iteration |
| -- scheme). |
| |
| Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange)); |
| Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype); |
| Set_Etype (Index_Subtype, Index_Type); |
| Set_Size_Info (Index_Subtype, Index_Type); |
| Set_RM_Size (Index_Subtype, RM_Size (Index_Type)); |
| end if; |
| |
| Slice_Subtype := Create_Itype (E_Array_Subtype, N); |
| |
| Index := New_Occurrence_Of (Index_Subtype, Loc); |
| Set_Etype (Index, Index_Subtype); |
| Append (Index, Index_List); |
| |
| Set_First_Index (Slice_Subtype, Index); |
| Set_Etype (Slice_Subtype, Base_Type (Etype (N))); |
| Set_Is_Constrained (Slice_Subtype, True); |
| |
| Check_Compile_Time_Size (Slice_Subtype); |
| |
| -- The Etype of the existing Slice node is reset to this slice subtype. |
| -- Its bounds are obtained from its first index. |
| |
| Set_Etype (N, Slice_Subtype); |
| |
| -- For packed slice subtypes, freeze immediately (except in the case of |
| -- being in a "spec expression" where we never freeze when we first see |
| -- the expression). |
| |
| if Is_Packed (Slice_Subtype) and not In_Spec_Expression then |
| Freeze_Itype (Slice_Subtype, N); |
| |
| -- For all other cases insert an itype reference in the slice's actions |
| -- so that the itype is frozen at the proper place in the tree (i.e. at |
| -- the point where actions for the slice are analyzed). Note that this |
| -- is different from freezing the itype immediately, which might be |
| -- premature (e.g. if the slice is within a transient scope). This needs |
| -- to be done only if expansion is enabled. |
| |
| elsif Expander_Active then |
| Ensure_Defined (Typ => Slice_Subtype, N => N); |
| end if; |
| end Set_Slice_Subtype; |
| |
| -------------------------------- |
| -- Set_String_Literal_Subtype -- |
| -------------------------------- |
| |
| procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Low_Bound : constant Node_Id := |
| Type_Low_Bound (Etype (First_Index (Typ))); |
| Subtype_Id : Entity_Id; |
| |
| begin |
| if Nkind (N) /= N_String_Literal then |
| return; |
| end if; |
| |
| Subtype_Id := Create_Itype (E_String_Literal_Subtype, N); |
| Set_String_Literal_Length (Subtype_Id, UI_From_Int |
| (String_Length (Strval (N)))); |
| Set_Etype (Subtype_Id, Base_Type (Typ)); |
| Set_Is_Constrained (Subtype_Id); |
| Set_Etype (N, Subtype_Id); |
| |
| -- The low bound is set from the low bound of the corresponding index |
| -- type. Note that we do not store the high bound in the string literal |
| -- subtype, but it can be deduced if necessary from the length and the |
| -- low bound. |
| |
| if Is_OK_Static_Expression (Low_Bound) then |
| Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound); |
| |
| -- If the lower bound is not static we create a range for the string |
| -- literal, using the index type and the known length of the literal. |
| -- The index type is not necessarily Positive, so the upper bound is |
| -- computed as T'Val (T'Pos (Low_Bound) + L - 1). |
| |
| else |
| declare |
| Index_List : constant List_Id := New_List; |
| Index_Type : constant Entity_Id := Etype (First_Index (Typ)); |
| High_Bound : constant Node_Id := |
| Make_Attribute_Reference (Loc, |
| Attribute_Name => Name_Val, |
| Prefix => |
| New_Occurrence_Of (Index_Type, Loc), |
| Expressions => New_List ( |
| Make_Op_Add (Loc, |
| Left_Opnd => |
| Make_Attribute_Reference (Loc, |
| Attribute_Name => Name_Pos, |
| Prefix => |
| New_Occurrence_Of (Index_Type, Loc), |
| Expressions => |
| New_List (New_Copy_Tree (Low_Bound))), |
| Right_Opnd => |
| Make_Integer_Literal (Loc, |
| String_Length (Strval (N)) - 1)))); |
| |
| Array_Subtype : Entity_Id; |
| Drange : Node_Id; |
| Index : Node_Id; |
| Index_Subtype : Entity_Id; |
| |
| begin |
| if Is_Integer_Type (Index_Type) then |
| Set_String_Literal_Low_Bound |
| (Subtype_Id, Make_Integer_Literal (Loc, 1)); |
| |
| else |
| -- If the index type is an enumeration type, build bounds |
| -- expression with attributes. |
| |
| Set_String_Literal_Low_Bound |
| (Subtype_Id, |
| Make_Attribute_Reference (Loc, |
| Attribute_Name => Name_First, |
| Prefix => |
| New_Occurrence_Of (Base_Type (Index_Type), Loc))); |
| Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type); |
| end if; |
| |
| Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id)); |
| |
| -- Build bona fide subtype for the string, and wrap it in an |
| -- unchecked conversion, because the backend expects the |
| -- String_Literal_Subtype to have a static lower bound. |
| |
| Index_Subtype := |
| Create_Itype (Subtype_Kind (Ekind (Index_Type)), N); |
| Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound); |
| Set_Scalar_Range (Index_Subtype, Drange); |
| Set_Parent (Drange, N); |
| Analyze_And_Resolve (Drange, Index_Type); |
| |
| -- In the context, the Index_Type may already have a constraint, |
| -- so use common base type on string subtype. The base type may |
| -- be used when generating attributes of the string, for example |
| -- in the context of a slice assignment. |
| |
| Set_Etype (Index_Subtype, Base_Type (Index_Type)); |
| Set_Size_Info (Index_Subtype, Index_Type); |
| Set_RM_Size (Index_Subtype, RM_Size (Index_Type)); |
| |
| Array_Subtype := Create_Itype (E_Array_Subtype, N); |
| |
| Index := New_Occurrence_Of (Index_Subtype, Loc); |
| Set_Etype (Index, Index_Subtype); |
| Append (Index, Index_List); |
| |
| Set_First_Index (Array_Subtype, Index); |
| Set_Etype (Array_Subtype, Base_Type (Typ)); |
| Set_Is_Constrained (Array_Subtype, True); |
| |
| Rewrite (N, |
| Make_Unchecked_Type_Conversion (Loc, |
| Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc), |
| Expression => Relocate_Node (N))); |
| Set_Etype (N, Array_Subtype); |
| end; |
| end if; |
| end Set_String_Literal_Subtype; |
| |
| ------------------------------ |
| -- Simplify_Type_Conversion -- |
| ------------------------------ |
| |
| procedure Simplify_Type_Conversion (N : Node_Id) is |
| begin |
| if Nkind (N) = N_Type_Conversion then |
| declare |
| Operand : constant Node_Id := Expression (N); |
| Target_Typ : constant Entity_Id := Etype (N); |
| Opnd_Typ : constant Entity_Id := Etype (Operand); |
| |
| begin |
| if Is_Floating_Point_Type (Opnd_Typ) |
| and then |
| (Is_Integer_Type (Target_Typ) |
| or else (Is_Fixed_Point_Type (Target_Typ) |
| and then Conversion_OK (N))) |
| and then Nkind (Operand) = N_Attribute_Reference |
| and then Attribute_Name (Operand) = Name_Truncation |
| |
| -- Special processing required if the conversion is the expression |
| -- of a Truncation attribute reference. In this case we replace: |
| |
| -- ityp (ftyp'Truncation (x)) |
| |
| -- by |
| |
| -- ityp (x) |
| |
| -- with the Float_Truncate flag set, which is more efficient. |
| |
| then |
| Rewrite (Operand, |
| Relocate_Node (First (Expressions (Operand)))); |
| Set_Float_Truncate (N, True); |
| end if; |
| end; |
| end if; |
| end Simplify_Type_Conversion; |
| |
| ----------------------------- |
| -- Unique_Fixed_Point_Type -- |
| ----------------------------- |
| |
| function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is |
| T1 : Entity_Id := Empty; |
| T2 : Entity_Id; |
| Item : Node_Id; |
| Scop : Entity_Id; |
| |
| procedure Fixed_Point_Error; |
| -- Give error messages for true ambiguity. Messages are posted on node |
| -- N, and entities T1, T2 are the possible interpretations. |
| |
| ----------------------- |
| -- Fixed_Point_Error -- |
| ----------------------- |
| |
| procedure Fixed_Point_Error is |
| begin |
| Error_Msg_N ("ambiguous universal_fixed_expression", N); |
| Error_Msg_NE ("\\possible interpretation as}", N, T1); |
| Error_Msg_NE ("\\possible interpretation as}", N, T2); |
| end Fixed_Point_Error; |
| |
| -- Start of processing for Unique_Fixed_Point_Type |
| |
| begin |
| -- The operations on Duration are visible, so Duration is always a |
| -- possible interpretation. |
| |
| T1 := Standard_Duration; |
| |
| -- Look for fixed-point types in enclosing scopes |
| |
| Scop := Current_Scope; |
| while Scop /= Standard_Standard loop |
| T2 := First_Entity (Scop); |
| while Present (T2) loop |
| if Is_Fixed_Point_Type (T2) |
| and then Current_Entity (T2) = T2 |
| and then Scope (Base_Type (T2)) = Scop |
| then |
| if Present (T1) then |
| Fixed_Point_Error; |
| return Any_Type; |
| else |
| T1 := T2; |
| end if; |
| end if; |
| |
| Next_Entity (T2); |
| end loop; |
| |
| Scop := Scope (Scop); |
| end loop; |
| |
| -- Look for visible fixed type declarations in the context |
| |
| Item := First (Context_Items (Cunit (Current_Sem_Unit))); |
| while Present (Item) loop |
| if Nkind (Item) = N_With_Clause then |
| Scop := Entity (Name (Item)); |
| T2 := First_Entity (Scop); |
| while Present (T2) loop |
| if Is_Fixed_Point_Type (T2) |
| and then Scope (Base_Type (T2)) = Scop |
| and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2)) |
| then |
| if Present (T1) then |
| Fixed_Point_Error; |
| return Any_Type; |
| else |
| T1 := T2; |
| end if; |
| end if; |
| |
| Next_Entity (T2); |
| end loop; |
| end if; |
| |
| Next (Item); |
| end loop; |
| |
| if Nkind (N) = N_Real_Literal then |
| Error_Msg_NE |
| ("??real literal interpreted as }!", N, T1); |
| else |
| Error_Msg_NE |
| ("??universal_fixed expression interpreted as }!", N, T1); |
| end if; |
| |
| return T1; |
| end Unique_Fixed_Point_Type; |
| |
| ---------------------- |
| -- Valid_Conversion -- |
| ---------------------- |
| |
| function Valid_Conversion |
| (N : Node_Id; |
| Target : Entity_Id; |
| Operand : Node_Id; |
| Report_Errs : Boolean := True) return Boolean |
| is |
| Target_Type : constant Entity_Id := Base_Type (Target); |
| Opnd_Type : Entity_Id := Etype (Operand); |
| Inc_Ancestor : Entity_Id; |
| |
| function Conversion_Check |
| (Valid : Boolean; |
| Msg : String) return Boolean; |
| -- Little routine to post Msg if Valid is False, returns Valid value |
| |
| procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id); |
| -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments |
| |
| procedure Conversion_Error_NE |
| (Msg : String; |
| N : Node_Or_Entity_Id; |
| E : Node_Or_Entity_Id); |
| -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments |
| |
| function Valid_Tagged_Conversion |
| (Target_Type : Entity_Id; |
| Opnd_Type : Entity_Id) return Boolean; |
| -- Specifically test for validity of tagged conversions |
| |
| function Valid_Array_Conversion return Boolean; |
| -- Check index and component conformance, and accessibility levels if |
| -- the component types are anonymous access types (Ada 2005). |
| |
| ---------------------- |
| -- Conversion_Check -- |
| ---------------------- |
| |
| function Conversion_Check |
| (Valid : Boolean; |
| Msg : String) return Boolean |
| is |
| begin |
| if not Valid |
| |
| -- A generic unit has already been analyzed and we have verified |
| -- that a particular conversion is OK in that context. Since the |
| -- instance is reanalyzed without relying on the relationships |
| -- established during the analysis of the generic, it is possible |
| -- to end up with inconsistent views of private types. Do not emit |
| -- the error message in such cases. The rest of the machinery in |
| -- Valid_Conversion still ensures the proper compatibility of |
| -- target and operand types. |
| |
| and then not In_Instance |
| then |
| Conversion_Error_N (Msg, Operand); |
| end if; |
| |
| return Valid; |
| end Conversion_Check; |
| |
| ------------------------ |
| -- Conversion_Error_N -- |
| ------------------------ |
| |
| procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id) is |
| begin |
| if Report_Errs then |
| Error_Msg_N (Msg, N); |
| end if; |
| end Conversion_Error_N; |
| |
| ------------------------- |
| -- Conversion_Error_NE -- |
| ------------------------- |
| |
| procedure Conversion_Error_NE |
| (Msg : String; |
| N : Node_Or_Entity_Id; |
| E : Node_Or_Entity_Id) |
| is |
| begin |
| if Report_Errs then |
| Error_Msg_NE (Msg, N, E); |
| end if; |
| end Conversion_Error_NE; |
| |
| ---------------------------- |
| -- Valid_Array_Conversion -- |
| ---------------------------- |
| |
| function Valid_Array_Conversion return Boolean |
| is |
| Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type); |
| Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type); |
| |
| Opnd_Index : Node_Id; |
| Opnd_Index_Type : Entity_Id; |
| |
| Target_Comp_Type : constant Entity_Id := |
| Component_Type (Target_Type); |
| Target_Comp_Base : constant Entity_Id := |
| Base_Type (Target_Comp_Type); |
| |
| Target_Index : Node_Id; |
| Target_Index_Type : Entity_Id; |
| |
| begin |
| -- Error if wrong number of dimensions |
| |
| if |
| Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type) |
| then |
| Conversion_Error_N |
| ("incompatible number of dimensions for conversion", Operand); |
| return False; |
| |
| -- Number of dimensions matches |
| |
| else |
| -- Loop through indexes of the two arrays |
| |
| Target_Index := First_Index (Target_Type); |
| Opnd_Index := First_Index (Opnd_Type); |
| while Present (Target_Index) and then Present (Opnd_Index) loop |
| Target_Index_Type := Etype (Target_Index); |
| Opnd_Index_Type := Etype (Opnd_Index); |
| |
| -- Error if index types are incompatible |
| |
| if not (Is_Integer_Type (Target_Index_Type) |
| and then Is_Integer_Type (Opnd_Index_Type)) |
| and then (Root_Type (Target_Index_Type) |
| /= Root_Type (Opnd_Index_Type)) |
| then |
| Conversion_Error_N |
| ("incompatible index types for array conversion", |
| Operand); |
| return False; |
| end if; |
| |
| Next_Index (Target_Index); |
| Next_Index (Opnd_Index); |
| end loop; |
| |
| -- If component types have same base type, all set |
| |
| if Target_Comp_Base = Opnd_Comp_Base then |
| null; |
| |
| -- Here if base types of components are not the same. The only |
| -- time this is allowed is if we have anonymous access types. |
| |
| -- The conversion of arrays of anonymous access types can lead |
| -- to dangling pointers. AI-392 formalizes the accessibility |
| -- checks that must be applied to such conversions to prevent |
| -- out-of-scope references. |
| |
| elsif Ekind_In |
| (Target_Comp_Base, E_Anonymous_Access_Type, |
| E_Anonymous_Access_Subprogram_Type) |
| and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base) |
| and then |
| Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type) |
| then |
| if Type_Access_Level (Target_Type) < |
| Deepest_Type_Access_Level (Opnd_Type) |
| then |
| if In_Instance_Body then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Conversion_Error_N |
| ("source array type has deeper accessibility " |
| & "level than target<<", Operand); |
| Conversion_Error_N ("\Program_Error [<<", Operand); |
| Rewrite (N, |
| Make_Raise_Program_Error (Sloc (N), |
| Reason => PE_Accessibility_Check_Failed)); |
| Set_Etype (N, Target_Type); |
| return False; |
| |
| -- Conversion not allowed because of accessibility levels |
| |
| else |
| Conversion_Error_N |
| ("source array type has deeper accessibility " |
| & "level than target", Operand); |
| return False; |
| end if; |
| |
| else |
| null; |
| end if; |
| |
| -- All other cases where component base types do not match |
| |
| else |
| Conversion_Error_N |
| ("incompatible component types for array conversion", |
| Operand); |
| return False; |
| end if; |
| |
| -- Check that component subtypes statically match. For numeric |
| -- types this means that both must be either constrained or |
| -- unconstrained. For enumeration types the bounds must match. |
| -- All of this is checked in Subtypes_Statically_Match. |
| |
| if not Subtypes_Statically_Match |
| (Target_Comp_Type, Opnd_Comp_Type) |
| then |
| Conversion_Error_N |
| ("component subtypes must statically match", Operand); |
| return False; |
| end if; |
| end if; |
| |
| return True; |
| end Valid_Array_Conversion; |
| |
| ----------------------------- |
| -- Valid_Tagged_Conversion -- |
| ----------------------------- |
| |
| function Valid_Tagged_Conversion |
| (Target_Type : Entity_Id; |
| Opnd_Type : Entity_Id) return Boolean |
| is |
| begin |
| -- Upward conversions are allowed (RM 4.6(22)) |
| |
| if Covers (Target_Type, Opnd_Type) |
| or else Is_Ancestor (Target_Type, Opnd_Type) |
| then |
| return True; |
| |
| -- Downward conversion are allowed if the operand is class-wide |
| -- (RM 4.6(23)). |
| |
| elsif Is_Class_Wide_Type (Opnd_Type) |
| and then Covers (Opnd_Type, Target_Type) |
| then |
| return True; |
| |
| elsif Covers (Opnd_Type, Target_Type) |
| or else Is_Ancestor (Opnd_Type, Target_Type) |
| then |
| return |
| Conversion_Check (False, |
| "downward conversion of tagged objects not allowed"); |
| |
| -- Ada 2005 (AI-251): The conversion to/from interface types is |
| -- always valid |
| |
| elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then |
| return True; |
| |
| -- If the operand is a class-wide type obtained through a limited_ |
| -- with clause, and the context includes the non-limited view, use |
| -- it to determine whether the conversion is legal. |
| |
| elsif Is_Class_Wide_Type (Opnd_Type) |
| and then From_Limited_With (Opnd_Type) |
| and then Present (Non_Limited_View (Etype (Opnd_Type))) |
| and then Is_Interface (Non_Limited_View (Etype (Opnd_Type))) |
| then |
| return True; |
| |
| elsif Is_Access_Type (Opnd_Type) |
| and then Is_Interface (Directly_Designated_Type (Opnd_Type)) |
| then |
| return True; |
| |
| else |
| Conversion_Error_NE |
| ("invalid tagged conversion, not compatible with}", |
| N, First_Subtype (Opnd_Type)); |
| return False; |
| end if; |
| end Valid_Tagged_Conversion; |
| |
| -- Start of processing for Valid_Conversion |
| |
| begin |
| Check_Parameterless_Call (Operand); |
| |
| if Is_Overloaded (Operand) then |
| declare |
| I : Interp_Index; |
| I1 : Interp_Index; |
| It : Interp; |
| It1 : Interp; |
| N1 : Entity_Id; |
| T1 : Entity_Id; |
| |
| begin |
| -- Remove procedure calls, which syntactically cannot appear in |
| -- this context, but which cannot be removed by type checking, |
| -- because the context does not impose a type. |
| |
| -- When compiling for VMS, spurious ambiguities can be produced |
| -- when arithmetic operations have a literal operand and return |
| -- System.Address or a descendant of it. These ambiguities are |
| -- otherwise resolved by the context, but for conversions there |
| -- is no context type and the removal of the spurious operations |
| -- must be done explicitly here. |
| |
| -- The node may be labelled overloaded, but still contain only one |
| -- interpretation because others were discarded earlier. If this |
| -- is the case, retain the single interpretation if legal. |
| |
| Get_First_Interp (Operand, I, It); |
| Opnd_Type := It.Typ; |
| Get_Next_Interp (I, It); |
| |
| if Present (It.Typ) |
| and then Opnd_Type /= Standard_Void_Type |
| then |
| -- More than one candidate interpretation is available |
| |
| Get_First_Interp (Operand, I, It); |
| while Present (It.Typ) loop |
| if It.Typ = Standard_Void_Type then |
| Remove_Interp (I); |
| end if; |
| |
| if Present (System_Aux_Id) |
| and then Is_Descendent_Of_Address (It.Typ) |
| then |
| Remove_Interp (I); |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end if; |
| |
| Get_First_Interp (Operand, I, It); |
| I1 := I; |
| It1 := It; |
| |
| if No (It.Typ) then |
| Conversion_Error_N ("illegal operand in conversion", Operand); |
| return False; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| |
| if Present (It.Typ) then |
| N1 := It1.Nam; |
| T1 := It1.Typ; |
| It1 := Disambiguate (Operand, I1, I, Any_Type); |
| |
| if It1 = No_Interp then |
| Conversion_Error_N |
| ("ambiguous operand in conversion", Operand); |
| |
| -- If the interpretation involves a standard operator, use |
| -- the location of the type, which may be user-defined. |
| |
| if Sloc (It.Nam) = Standard_Location then |
| Error_Msg_Sloc := Sloc (It.Typ); |
| else |
| Error_Msg_Sloc := Sloc (It.Nam); |
| end if; |
| |
| Conversion_Error_N -- CODEFIX |
| ("\\possible interpretation#!", Operand); |
| |
| if Sloc (N1) = Standard_Location then |
| Error_Msg_Sloc := Sloc (T1); |
| else |
| Error_Msg_Sloc := Sloc (N1); |
| end if; |
| |
| Conversion_Error_N -- CODEFIX |
| ("\\possible interpretation#!", Operand); |
| |
| return False; |
| end if; |
| end if; |
| |
| Set_Etype (Operand, It1.Typ); |
| Opnd_Type := It1.Typ; |
| end; |
| end if; |
| |
| -- Deal with conversion of integer type to address if the pragma |
| -- Allow_Integer_Address is in effect. We convert the conversion to |
| -- an unchecked conversion in this case and we are all done. |
| |
| if Address_Integer_Convert_OK (Opnd_Type, Target_Type) then |
| Rewrite (N, Unchecked_Convert_To (Target_Type, Expression (N))); |
| Analyze_And_Resolve (N, Target_Type); |
| return True; |
| end if; |
| |
| -- If we are within a child unit, check whether the type of the |
| -- expression has an ancestor in a parent unit, in which case it |
| -- belongs to its derivation class even if the ancestor is private. |
| -- See RM 7.3.1 (5.2/3). |
| |
| Inc_Ancestor := Get_Incomplete_View_Of_Ancestor (Opnd_Type); |
| |
| -- Numeric types |
| |
| if Is_Numeric_Type (Target_Type) then |
| |
| -- A universal fixed expression can be converted to any numeric type |
| |
| if Opnd_Type = Universal_Fixed then |
| return True; |
| |
| -- Also no need to check when in an instance or inlined body, because |
| -- the legality has been established when the template was analyzed. |
| -- Furthermore, numeric conversions may occur where only a private |
| -- view of the operand type is visible at the instantiation point. |
| -- This results in a spurious error if we check that the operand type |
| -- is a numeric type. |
| |
| -- Note: in a previous version of this unit, the following tests were |
| -- applied only for generated code (Comes_From_Source set to False), |
| -- but in fact the test is required for source code as well, since |
| -- this situation can arise in source code. |
| |
| elsif In_Instance or else In_Inlined_Body then |
| return True; |
| |
| -- Otherwise we need the conversion check |
| |
| else |
| return Conversion_Check |
| (Is_Numeric_Type (Opnd_Type) |
| or else |
| (Present (Inc_Ancestor) |
| and then Is_Numeric_Type (Inc_Ancestor)), |
| "illegal operand for numeric conversion"); |
| end if; |
| |
| -- Array types |
| |
| elsif Is_Array_Type (Target_Type) then |
| if not Is_Array_Type (Opnd_Type) |
| or else Opnd_Type = Any_Composite |
| or else Opnd_Type = Any_String |
| then |
| Conversion_Error_N |
| ("illegal operand for array conversion", Operand); |
| return False; |
| |
| else |
| return Valid_Array_Conversion; |
| end if; |
| |
| -- Ada 2005 (AI-251): Anonymous access types where target references an |
| -- interface type. |
| |
| elsif Ekind_In (Target_Type, E_General_Access_Type, |
| E_Anonymous_Access_Type) |
| and then Is_Interface (Directly_Designated_Type (Target_Type)) |
| then |
| -- Check the static accessibility rule of 4.6(17). Note that the |
| -- check is not enforced when within an instance body, since the |
| -- RM requires such cases to be caught at run time. |
| |
| -- If the operand is a rewriting of an allocator no check is needed |
| -- because there are no accessibility issues. |
| |
| if Nkind (Original_Node (N)) = N_Allocator then |
| null; |
| |
| elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then |
| if Type_Access_Level (Opnd_Type) > |
| Deepest_Type_Access_Level (Target_Type) |
| then |
| -- In an instance, this is a run-time check, but one we know |
| -- will fail, so generate an appropriate warning. The raise |
| -- will be generated by Expand_N_Type_Conversion. |
| |
| if In_Instance_Body then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Conversion_Error_N |
| ("cannot convert local pointer to non-local access type<<", |
| Operand); |
| Conversion_Error_N ("\Program_Error [<<", Operand); |
| |
| else |
| Conversion_Error_N |
| ("cannot convert local pointer to non-local access type", |
| Operand); |
| return False; |
| end if; |
| |
| -- Special accessibility checks are needed in the case of access |
| -- discriminants declared for a limited type. |
| |
| elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type |
| and then not Is_Local_Anonymous_Access (Opnd_Type) |
| then |
| -- When the operand is a selected access discriminant the check |
| -- needs to be made against the level of the object denoted by |
| -- the prefix of the selected name (Object_Access_Level handles |
| -- checking the prefix of the operand for this case). |
| |
| if Nkind (Operand) = N_Selected_Component |
| and then Object_Access_Level (Operand) > |
| Deepest_Type_Access_Level (Target_Type) |
| then |
| -- In an instance, this is a run-time check, but one we know |
| -- will fail, so generate an appropriate warning. The raise |
| -- will be generated by Expand_N_Type_Conversion. |
| |
| if In_Instance_Body then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Conversion_Error_N |
| ("cannot convert access discriminant to non-local " |
| & "access type<<", Operand); |
| Conversion_Error_N ("\Program_Error [<<", Operand); |
| |
| -- Real error if not in instance body |
| |
| else |
| Conversion_Error_N |
| ("cannot convert access discriminant to non-local " |
| & "access type", Operand); |
| return False; |
| end if; |
| end if; |
| |
| -- The case of a reference to an access discriminant from |
| -- within a limited type declaration (which will appear as |
| -- a discriminal) is always illegal because the level of the |
| -- discriminant is considered to be deeper than any (nameable) |
| -- access type. |
| |
| if Is_Entity_Name (Operand) |
| and then not Is_Local_Anonymous_Access (Opnd_Type) |
| and then |
| Ekind_In (Entity (Operand), E_In_Parameter, E_Constant) |
| and then Present (Discriminal_Link (Entity (Operand))) |
| then |
| Conversion_Error_N |
| ("discriminant has deeper accessibility level than target", |
| Operand); |
| return False; |
| end if; |
| end if; |
| end if; |
| |
| return True; |
| |
| -- General and anonymous access types |
| |
| elsif Ekind_In (Target_Type, E_General_Access_Type, |
| E_Anonymous_Access_Type) |
| and then |
| Conversion_Check |
| (Is_Access_Type (Opnd_Type) |
| and then not |
| Ekind_In (Opnd_Type, E_Access_Subprogram_Type, |
| E_Access_Protected_Subprogram_Type), |
| "must be an access-to-object type") |
| then |
| if Is_Access_Constant (Opnd_Type) |
| and then not Is_Access_Constant (Target_Type) |
| then |
| Conversion_Error_N |
| ("access-to-constant operand type not allowed", Operand); |
| return False; |
| end if; |
| |
| -- Check the static accessibility rule of 4.6(17). Note that the |
| -- check is not enforced when within an instance body, since the RM |
| -- requires such cases to be caught at run time. |
| |
| if Ekind (Target_Type) /= E_Anonymous_Access_Type |
| or else Is_Local_Anonymous_Access (Target_Type) |
| or else Nkind (Associated_Node_For_Itype (Target_Type)) = |
| N_Object_Declaration |
| then |
| -- Ada 2012 (AI05-0149): Perform legality checking on implicit |
| -- conversions from an anonymous access type to a named general |
| -- access type. Such conversions are not allowed in the case of |
| -- access parameters and stand-alone objects of an anonymous |
| -- access type. The implicit conversion case is recognized by |
| -- testing that Comes_From_Source is False and that it's been |
| -- rewritten. The Comes_From_Source test isn't sufficient because |
| -- nodes in inlined calls to predefined library routines can have |
| -- Comes_From_Source set to False. (Is there a better way to test |
| -- for implicit conversions???) |
| |
| if Ada_Version >= Ada_2012 |
| and then not Comes_From_Source (N) |
| and then N /= Original_Node (N) |
| and then Ekind (Target_Type) = E_General_Access_Type |
| and then Ekind (Opnd_Type) = E_Anonymous_Access_Type |
| then |
| if Is_Itype (Opnd_Type) then |
| |
| -- Implicit conversions aren't allowed for objects of an |
| -- anonymous access type, since such objects have nonstatic |
| -- levels in Ada 2012. |
| |
| if Nkind (Associated_Node_For_Itype (Opnd_Type)) = |
| N_Object_Declaration |
| then |
| Conversion_Error_N |
| ("implicit conversion of stand-alone anonymous " |
| & "access object not allowed", Operand); |
| return False; |
| |
| -- Implicit conversions aren't allowed for anonymous access |
| -- parameters. The "not Is_Local_Anonymous_Access_Type" test |
| -- is done to exclude anonymous access results. |
| |
| elsif not Is_Local_Anonymous_Access (Opnd_Type) |
| and then Nkind_In (Associated_Node_For_Itype (Opnd_Type), |
| N_Function_Specification, |
| N_Procedure_Specification) |
| then |
| Conversion_Error_N |
| ("implicit conversion of anonymous access formal " |
| & "not allowed", Operand); |
| return False; |
| |
| -- This is a case where there's an enclosing object whose |
| -- to which the "statically deeper than" relationship does |
| -- not apply (such as an access discriminant selected from |
| -- a dereference of an access parameter). |
| |
| elsif Object_Access_Level (Operand) |
| = Scope_Depth (Standard_Standard) |
| then |
| Conversion_Error_N |
| ("implicit conversion of anonymous access value " |
| & "not allowed", Operand); |
| return False; |
| |
| -- In other cases, the level of the operand's type must be |
| -- statically less deep than that of the target type, else |
| -- implicit conversion is disallowed (by RM12-8.6(27.1/3)). |
| |
| elsif Type_Access_Level (Opnd_Type) > |
| Deepest_Type_Access_Level (Target_Type) |
| then |
| Conversion_Error_N |
| ("implicit conversion of anonymous access value " |
| & "violates accessibility", Operand); |
| return False; |
| end if; |
| end if; |
| |
| elsif Type_Access_Level (Opnd_Type) > |
| Deepest_Type_Access_Level (Target_Type) |
| then |
| -- In an instance, this is a run-time check, but one we know |
| -- will fail, so generate an appropriate warning. The raise |
| -- will be generated by Expand_N_Type_Conversion. |
| |
| if In_Instance_Body then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Conversion_Error_N |
| ("cannot convert local pointer to non-local access type<<", |
| Operand); |
| Conversion_Error_N ("\Program_Error [<<", Operand); |
| |
| -- If not in an instance body, this is a real error |
| |
| else |
| -- Avoid generation of spurious error message |
| |
| if not Error_Posted (N) then |
| Conversion_Error_N |
| ("cannot convert local pointer to non-local access type", |
| Operand); |
| end if; |
| |
| return False; |
| end if; |
| |
| -- Special accessibility checks are needed in the case of access |
| -- discriminants declared for a limited type. |
| |
| elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type |
| and then not Is_Local_Anonymous_Access (Opnd_Type) |
| then |
| -- When the operand is a selected access discriminant the check |
| -- needs to be made against the level of the object denoted by |
| -- the prefix of the selected name (Object_Access_Level handles |
| -- checking the prefix of the operand for this case). |
| |
| if Nkind (Operand) = N_Selected_Component |
| and then Object_Access_Level (Operand) > |
| Deepest_Type_Access_Level (Target_Type) |
| then |
| -- In an instance, this is a run-time check, but one we know |
| -- will fail, so generate an appropriate warning. The raise |
| -- will be generated by Expand_N_Type_Conversion. |
| |
| if In_Instance_Body then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Conversion_Error_N |
| ("cannot convert access discriminant to non-local " |
| & "access type<<", Operand); |
| Conversion_Error_N ("\Program_Error [<<", Operand); |
| |
| -- If not in an instance body, this is a real error |
| |
| else |
| Conversion_Error_N |
| ("cannot convert access discriminant to non-local " |
| & "access type", Operand); |
| return False; |
| end if; |
| end if; |
| |
| -- The case of a reference to an access discriminant from |
| -- within a limited type declaration (which will appear as |
| -- a discriminal) is always illegal because the level of the |
| -- discriminant is considered to be deeper than any (nameable) |
| -- access type. |
| |
| if Is_Entity_Name (Operand) |
| and then |
| Ekind_In (Entity (Operand), E_In_Parameter, E_Constant) |
| and then Present (Discriminal_Link (Entity (Operand))) |
| then |
| Conversion_Error_N |
| ("discriminant has deeper accessibility level than target", |
| Operand); |
| return False; |
| end if; |
| end if; |
| end if; |
| |
| -- In the presence of limited_with clauses we have to use non-limited |
| -- views, if available. |
| |
| Check_Limited : declare |
| function Full_Designated_Type (T : Entity_Id) return Entity_Id; |
| -- Helper function to handle limited views |
| |
| -------------------------- |
| -- Full_Designated_Type -- |
| -------------------------- |
| |
| function Full_Designated_Type (T : Entity_Id) return Entity_Id is |
| Desig : constant Entity_Id := Designated_Type (T); |
| |
| begin |
| -- Handle the limited view of a type |
| |
| if Is_Incomplete_Type (Desig) |
| and then From_Limited_With (Desig) |
| and then Present (Non_Limited_View (Desig)) |
| then |
| return Available_View (Desig); |
| else |
| return Desig; |
| end if; |
| end Full_Designated_Type; |
| |
| -- Local Declarations |
| |
| Target : constant Entity_Id := Full_Designated_Type (Target_Type); |
| Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type); |
| |
| Same_Base : constant Boolean := |
| Base_Type (Target) = Base_Type (Opnd); |
| |
| -- Start of processing for Check_Limited |
| |
| begin |
| if Is_Tagged_Type (Target) then |
| return Valid_Tagged_Conversion (Target, Opnd); |
| |
| else |
| if not Same_Base then |
| Conversion_Error_NE |
| ("target designated type not compatible with }", |
| N, Base_Type (Opnd)); |
| return False; |
| |
| -- Ada 2005 AI-384: legality rule is symmetric in both |
| -- designated types. The conversion is legal (with possible |
| -- constraint check) if either designated type is |
| -- unconstrained. |
| |
| elsif Subtypes_Statically_Match (Target, Opnd) |
| or else |
| (Has_Discriminants (Target) |
| and then |
| (not Is_Constrained (Opnd) |
| or else not Is_Constrained (Target))) |
| then |
| -- Special case, if Value_Size has been used to make the |
| -- sizes different, the conversion is not allowed even |
| -- though the subtypes statically match. |
| |
| if Known_Static_RM_Size (Target) |
| and then Known_Static_RM_Size (Opnd) |
| and then RM_Size (Target) /= RM_Size (Opnd) |
| then |
| Conversion_Error_NE |
| ("target designated subtype not compatible with }", |
| N, Opnd); |
| Conversion_Error_NE |
| ("\because sizes of the two designated subtypes differ", |
| N, Opnd); |
| return False; |
| |
| -- Normal case where conversion is allowed |
| |
| else |
| return True; |
| end if; |
| |
| else |
| Error_Msg_NE |
| ("target designated subtype not compatible with }", |
| N, Opnd); |
| return False; |
| end if; |
| end if; |
| end Check_Limited; |
| |
| -- Access to subprogram types. If the operand is an access parameter, |
| -- the type has a deeper accessibility that any master, and cannot be |
| -- assigned. We must make an exception if the conversion is part of an |
| -- assignment and the target is the return object of an extended return |
| -- statement, because in that case the accessibility check takes place |
| -- after the return. |
| |
| elsif Is_Access_Subprogram_Type (Target_Type) |
| and then No (Corresponding_Remote_Type (Opnd_Type)) |
| then |
| if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type |
| and then Is_Entity_Name (Operand) |
| and then Ekind (Entity (Operand)) = E_In_Parameter |
| and then |
| (Nkind (Parent (N)) /= N_Assignment_Statement |
| or else not Is_Entity_Name (Name (Parent (N))) |
| or else not Is_Return_Object (Entity (Name (Parent (N))))) |
| then |
| Conversion_Error_N |
| ("illegal attempt to store anonymous access to subprogram", |
| Operand); |
| Conversion_Error_N |
| ("\value has deeper accessibility than any master " |
| & "(RM 3.10.2 (13))", |
| Operand); |
| |
| Error_Msg_NE |
| ("\use named access type for& instead of access parameter", |
| Operand, Entity (Operand)); |
| end if; |
| |
| -- Check that the designated types are subtype conformant |
| |
| Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type), |
| Old_Id => Designated_Type (Opnd_Type), |
| Err_Loc => N); |
| |
| -- Check the static accessibility rule of 4.6(20) |
| |
| if Type_Access_Level (Opnd_Type) > |
| Deepest_Type_Access_Level (Target_Type) |
| then |
| Conversion_Error_N |
| ("operand type has deeper accessibility level than target", |
| Operand); |
| |
| -- Check that if the operand type is declared in a generic body, |
| -- then the target type must be declared within that same body |
| -- (enforces last sentence of 4.6(20)). |
| |
| elsif Present (Enclosing_Generic_Body (Opnd_Type)) then |
| declare |
| O_Gen : constant Node_Id := |
| Enclosing_Generic_Body (Opnd_Type); |
| |
| T_Gen : Node_Id; |
| |
| begin |
| T_Gen := Enclosing_Generic_Body (Target_Type); |
| while Present (T_Gen) and then T_Gen /= O_Gen loop |
| T_Gen := Enclosing_Generic_Body (T_Gen); |
| end loop; |
| |
| if T_Gen /= O_Gen then |
| Conversion_Error_N |
| ("target type must be declared in same generic body " |
| & "as operand type", N); |
| end if; |
| end; |
| end if; |
| |
| return True; |
| |
| -- Remote subprogram access types |
| |
| elsif Is_Remote_Access_To_Subprogram_Type (Target_Type) |
| and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type) |
| then |
| -- It is valid to convert from one RAS type to another provided |
| -- that their specification statically match. |
| |
| Check_Subtype_Conformant |
| (New_Id => |
| Designated_Type (Corresponding_Remote_Type (Target_Type)), |
| Old_Id => |
| Designated_Type (Corresponding_Remote_Type (Opnd_Type)), |
| Err_Loc => |
| N); |
| return True; |
| |
| -- If it was legal in the generic, it's legal in the instance |
| |
| elsif In_Instance_Body then |
| return True; |
| |
| -- If both are tagged types, check legality of view conversions |
| |
| elsif Is_Tagged_Type (Target_Type) |
| and then |
| Is_Tagged_Type (Opnd_Type) |
| then |
| return Valid_Tagged_Conversion (Target_Type, Opnd_Type); |
| |
| -- Types derived from the same root type are convertible |
| |
| elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then |
| return True; |
| |
| -- In an instance or an inlined body, there may be inconsistent views of |
| -- the same type, or of types derived from a common root. |
| |
| elsif (In_Instance or In_Inlined_Body) |
| and then |
| Root_Type (Underlying_Type (Target_Type)) = |
| Root_Type (Underlying_Type (Opnd_Type)) |
| then |
| return True; |
| |
| -- Special check for common access type error case |
| |
| elsif Ekind (Target_Type) = E_Access_Type |
| and then Is_Access_Type (Opnd_Type) |
| then |
| Conversion_Error_N ("target type must be general access type!", N); |
| Conversion_Error_NE -- CODEFIX |
| ("add ALL to }!", N, Target_Type); |
| return False; |
| |
| -- Here we have a real conversion error |
| |
| else |
| Conversion_Error_NE |
| ("invalid conversion, not compatible with }", N, Opnd_Type); |
| return False; |
| end if; |
| end Valid_Conversion; |
| |
| end Sem_Res; |